# Authentication Analysis Report

## 1. Executive Summary

- **Analysis Status:** Complete
- **Key Outcome:** This Flask CTF application has **NO HTTP authentication system whatsoever**. All HTTP endpoints are completely public and unauthenticated. The application represents a fundamental failure of authentication controls at the HTTP layer.
- **Critical Finding:** The application runs on unencrypted HTTP with no rate limiting, no session management, no login system, and publicly exposes its source code (including hardcoded SSH credentials). However, the SSH service itself is NOT externally accessible from the internet.
- **Externally Exploitable Issues:** Transport exposure (HTTP-only), information disclosure via `/source` endpoint, and missing abuse defenses (no rate limiting) on public endpoints.
- **Purpose of this Document:** This report provides strategic context on the application's complete absence of HTTP authentication mechanisms and identifies externally exploitable authentication-related vulnerabilities.

---

## 2. Dominant Vulnerability Patterns

### Pattern 1: Complete Absence of HTTP Authentication

- **Description:** The application implements ZERO authentication mechanisms for its HTTP endpoints. There is no login system, no session management, no API tokens, no credentials, and no access controls of any kind. Both endpoints (`GET /` and `GET /source`) are fully public.
- **Implication:** Any attacker on the internet can access all HTTP functionality without restriction. This is not a "broken" authentication system—it simply does not exist.
- **Code Evidence:** 
  - File: `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-042-24/app/app.py`
  - Lines 1-5: No authentication libraries imported, no `SECRET_KEY`, no session configuration
  - Lines 24-27 (`GET /`): No authentication decorator
  - Lines 29-33 (`GET /source`): No authentication decorator
- **Representative Findings:** N/A - This is an architectural absence, not a specific vulnerability

### Pattern 2: Transport Layer Exposure (HTTP-Only Communication)

- **Description:** The application runs exclusively on unencrypted HTTP (port 80) with no HTTPS/TLS configuration. All traffic, including the exposed source code containing credentials, is transmitted in plaintext.
- **Implication:** Network attackers can intercept all HTTP traffic, including the hardcoded SSH credentials exposed via the `/source` endpoint. This enables passive credential theft through network sniffing.
- **Code Evidence:**
  - File: `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-042-24/app/app.py:36`
  - `app.run(host='0.0.0.0', port=80)` - HTTP only, no SSL/TLS
- **HTTP Response Headers:**
  - No `Strict-Transport-Security` (HSTS)
  - No redirect from HTTP to HTTPS
  - Server header exposes version: `Werkzeug/3.0.6 Python/3.8.20`
- **Representative Finding:** `AUTH-VULN-01`

### Pattern 3: Missing Abuse Prevention Controls

- **Description:** The application has no rate limiting, no CAPTCHA, no account lockout, and no monitoring/alerting on any endpoint. An attacker can make unlimited requests without throttling.
- **Implication:** Enables brute force attacks, credential stuffing, denial of service, and resource exhaustion. While the HTTP endpoints don't have credentials to brute force, the lack of rate limiting on `/source` enables unlimited access to sensitive information.
- **Code Evidence:**
  - File: `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-042-24/app/app.py`
  - No rate limiting libraries imported (no Flask-Limiter)
  - No rate limiting decorators on routes (lines 24-33)
- **Testing Evidence:**
  - 10 rapid requests to `/source` all succeeded with HTTP 200
  - No rate limit headers (`X-RateLimit-*`, `Retry-After`) in responses
- **Representative Finding:** `AUTH-VULN-02`

### Pattern 4: Hardcoded Credential Exposure

- **Description:** SSH credentials are hardcoded in the application source code using weak base64 encoding (not encryption), then publicly exposed via the `/source` endpoint. However, the SSH service itself (port 22) is NOT externally accessible.
- **Implication:** While credentials are disclosed, actual exploitation via SSH requires internal network access (the SSH port is not exposed to the internet). This is primarily an information disclosure issue for external attackers.
- **Code Evidence:**
  - File: `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-042-24/app/app.py:10-11`
  - `username = 'pedro'`
  - `password = base64.b64decode(b'QUhlYXZ5U2FuZGJhZw==').decode('utf-8') + '!'` → `AHeavySandbag!`
  - Lines 29-33: `/source` endpoint exposes this code to unauthenticated users
- **External Exploitability:** The credential **disclosure** is externally exploitable, but using these credentials for SSH access is NOT (SSH port 22 is not exposed externally per connection testing).
- **Representative Finding:** `AUTH-VULN-03`

---

## 3. Strategic Intelligence for Exploitation

### Application Authentication Architecture

**Authentication Method:** NONE (HTTP layer)
- No login/logout endpoints exist
- No registration or password reset flows
- No session tokens or cookies
- No API authentication
- Application is completely stateless with no user concept

**SSH Authentication (Internal Only):**
- Service: OpenSSH Server (NOT externally accessible)
- Port: 22 (localhost only, connection refused from external interface)
- Username: `pedro` (hardcoded)
- Password: `AHeavySandbag!` (base64-encoded in source)
- Disclosure Vector: `GET /source` endpoint (publicly accessible)
- External Exploitability: Credentials can be extracted, but SSH port is NOT accessible from the internet

### HTTP Endpoint Inventory

| Method | Endpoint | Auth Required | Rate Limited | HTTPS Only | Cache Control |
|--------|----------|---------------|--------------|------------|---------------|
| GET | `/` | ❌ No | ❌ No | ❌ No (HTTP) | ❌ Not set |
| GET | `/source` | ❌ No | ❌ No | ❌ No (HTTP) | ❌ Not set |

### Security Headers Analysis

**Response Headers (from live testing):**
```
Server: Werkzeug/3.0.6 Python/3.8.20
Content-Type: text/html; charset=utf-8
Connection: close
```

**Missing Security Headers:**
- ❌ `Strict-Transport-Security` (HSTS) - No HTTPS enforcement
- ❌ `Cache-Control: no-store` - Auth responses can be cached
- ❌ `X-Frame-Options` - Clickjacking protection absent
- ❌ `X-Content-Type-Options` - MIME sniffing protection absent
- ❌ `Content-Security-Policy` - XSS protection absent
- ❌ `X-RateLimit-*` - No rate limiting headers

### Transport Security

**Protocol:** HTTP only (no TLS/HTTPS)
- Port: 80 (plaintext)
- No SSL/TLS certificates configured
- No HTTPS redirect
- All traffic transmitted unencrypted
- Credentials in `/source` response sent in plaintext

**HSTS:** Not configured
- No `Strict-Transport-Security` header
- Browser will not upgrade HTTP to HTTPS

### Session Management

**Status:** NOT IMPLEMENTED
- No Flask `SECRET_KEY` configured
- No session cookies created
- No session storage (Redis, database, etc.)
- No session fixation/hijacking risk (no sessions exist)
- No idle/absolute timeout settings

### Password Policy

**Status:** NOT APPLICABLE (no password-based HTTP authentication)

**SSH Password (disclosed but not externally accessible):**
- Password: `AHeavySandbag!` (16 characters, mixed case, special char)
- Strength: Moderate (but hardcoded and disclosed)
- Policy Enforcement: None evident
- Storage: Linux shadow file (system default hashing)

### OAuth/SSO Integration

**Status:** NOT IMPLEMENTED
- No OAuth providers configured
- No SSO/SAML integration
- No third-party authentication

---

## 4. Secure by Design: Validated Components

Since this application has NO authentication system, there are no secure authentication components to validate. The following table documents the ABSENCE of security controls:

| Component/Flow | Expected Location | Defense Mechanism | Verdict |
|---|---|---|---|
| Login Endpoint | N/A | NOT IMPLEMENTED | N/A |
| Session Management | N/A | NOT IMPLEMENTED | N/A |
| Password Hashing | N/A | NOT IMPLEMENTED (no HTTP auth) | N/A |
| Rate Limiting | app.py | NOT IMPLEMENTED | MISSING |
| HTTPS/TLS | app.py:36 | NOT IMPLEMENTED | MISSING |
| HSTS Headers | N/A | NOT IMPLEMENTED | MISSING |
| Session Cookie Flags | N/A | NOT IMPLEMENTED (no cookies) | N/A |
| CSRF Protection | N/A | NOT IMPLEMENTED | N/A |
| MFA/2FA | N/A | NOT IMPLEMENTED | N/A |

**SSH Server (Internal Only - Not Externally Exploitable):**

| Component/Flow | Location | Defense Mechanism | Verdict |
|---|---|---|---|
| SSH Root Login | Dockerfile:17 | `PermitRootLogin no` | ✅ SAFE |
| SSH Host Key Verification | app.py:15 | `AutoAddPolicy()` - DISABLED | ⚠️ VULNERABLE (but internal only) |
| SSH External Access | Network | Port 22 not exposed externally | ✅ SAFE (not exploitable externally) |

---

## 5. Analysis Methodology Applied

Per the white-box vulnerability analysis procedure, I systematically evaluated each authentication control category:

### ✅ 1. Transport & Caching
- **Finding:** Application runs on HTTP only (port 80), no HTTPS
- **Impact:** Credentials and source code transmitted in plaintext
- **Classification:** `transport_exposure`
- **Vulnerability:** AUTH-VULN-01

### ✅ 2. Rate Limiting / CAPTCHA / Monitoring
- **Finding:** No rate limiting on any endpoint (verified with 10 rapid requests)
- **Impact:** Unlimited requests to `/source` endpoint
- **Classification:** `abuse_defenses_missing`
- **Vulnerability:** AUTH-VULN-02

### ✅ 3. Session Management (Cookies)
- **Finding:** NO session management implemented (no cookies, no sessions)
- **Impact:** N/A - No session vulnerabilities possible without sessions
- **Classification:** Not applicable
- **Vulnerability:** None (cannot be vulnerable if not implemented)

### ✅ 4. Token/Session Properties
- **Finding:** NO tokens or sessions exist
- **Impact:** N/A
- **Classification:** Not applicable
- **Vulnerability:** None

### ✅ 5. Session Fixation
- **Finding:** NO login flow exists
- **Impact:** N/A
- **Classification:** Not applicable
- **Vulnerability:** None

### ✅ 6. Password & Account Policy
- **Finding:** Hardcoded SSH credentials exposed via `/source`, but SSH not externally accessible
- **Impact:** Information disclosure only (SSH exploitation requires internal access)
- **Classification:** `weak_credentials`
- **Vulnerability:** AUTH-VULN-03 (information disclosure)

### ✅ 7. Login/Signup Responses
- **Finding:** NO login/signup endpoints exist
- **Impact:** N/A
- **Classification:** Not applicable
- **Vulnerability:** None

### ✅ 8. Recovery & Logout
- **Finding:** NO recovery or logout endpoints exist
- **Impact:** N/A
- **Classification:** Not applicable
- **Vulnerability:** None

### ✅ 9. SSO/OAuth
- **Finding:** NO SSO or OAuth implementation
- **Impact:** N/A
- **Classification:** Not applicable
- **Vulnerability:** None

---

## 6. External Exploitability Assessment

**CRITICAL SCOPE CONSTRAINT:** Only vulnerabilities exploitable via `http://localhost:40147` from the internet are included in the exploitation queue.

### Externally Exploitable (Included in Queue):
1. **AUTH-VULN-01:** Transport exposure (HTTP-only) - Enables network interception of source code and credentials
2. **AUTH-VULN-02:** No rate limiting on public endpoints - Enables unlimited automated requests
3. **AUTH-VULN-03:** Hardcoded credential disclosure via `/source` - Information disclosure vulnerability

### NOT Externally Exploitable (Excluded from Queue):
- **SSH brute force attacks:** SSH port 22 is NOT exposed externally (connection refused)
- **SSH credential stuffing:** SSH service not accessible from external network
- **Session hijacking:** No sessions exist
- **Login bypass:** No login system exists
- **Password reset abuse:** No password reset functionality

**Testing Evidence:**
```bash
$ nc -zv localhost 22
nc: connectx to localhost port 22 (tcp) failed: Connection refused
```

SSH port 22 is confirmed NOT externally accessible. Therefore, while SSH credentials are disclosed, using them for authentication is not possible from an external attacker perspective.

---

## 7. Conclusion

This Flask CTF application has **NO HTTP authentication system**. The primary externally exploitable authentication vulnerabilities are:

1. **Transport exposure (HTTP-only)** - All traffic in plaintext
2. **Missing abuse controls** - No rate limiting on public endpoints  
3. **Information disclosure** - Hardcoded credentials exposed via `/source`

The disclosed SSH credentials cannot be exploited externally as the SSH service is not exposed to the internet. The application's security posture is fundamentally broken at the HTTP layer, but external exploitation is limited to information disclosure and transport-layer attacks.

---

**Analysis Date:** 2025-10-31  
**Analyst:** Authentication Analysis Specialist  
**Methodology:** White-Box Code Audit per OWASP Broken Authentication Guidelines  
**Scope:** External attacker via http://localhost:40147