# Authentication Analysis Report

## 1. Executive Summary
- **Analysis Status:** Complete
- **Key Outcome:** Critical authentication vulnerabilities were identified across all major authentication controls. The application demonstrates a complete failure of authentication security, with the most severe being JWT algorithm confusion (none algorithm + disabled signature verification) enabling trivial authentication bypass and privilege escalation.
- **Purpose of this Document:** This report provides strategic context on the application's authentication mechanisms, dominant flaw patterns, and architectural details necessary to effectively exploit the vulnerabilities documented in the exploitation queue.

## 2. Dominant Vulnerability Patterns

### Pattern 1: JWT Algorithm Confusion and Signature Bypass (CRITICAL)
- **Description:** The application uses JWT tokens with `algorithm='none'` (no cryptographic signature) and explicitly disables signature verification with `verify_signature: False`. This represents a complete breakdown of token integrity protection.
- **Code Evidence:**
  - Token creation: `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-091-24/app/app.py` line 27: `jwt.encode({"username": username, "role": users[username]['role']}, '', algorithm='none')`
  - Token validation: Lines 44 and 61: `jwt.decode(token, options={"verify_signature": False})`
- **Implication:** Any attacker can forge JWT tokens with arbitrary username and role claims (e.g., `{"username": "attacker", "role": "admin"}`) without possessing any secret key. The forged token will be accepted by the application as valid.
- **Representative Findings:** `AUTH-VULN-01`, `AUTH-VULN-02`.

### Pattern 2: Complete Absence of Session Management Security Controls
- **Description:** The application fails to implement fundamental session security controls including cookie security flags, session expiration, logout functionality, and session fixation protection.
- **Code Evidence:**
  - Cookie configuration: Line 30: `resp.set_cookie('token', token)` - no HttpOnly, Secure, SameSite, or Max-Age flags
  - No logout endpoint: Application has only 4 routes (`/`, `/login`, `/profile`, `/dashboard`) - no `/logout` exists
  - No expiration: JWT payload contains no `exp`, `iat`, or `jti` claims
- **Implication:** Compromised tokens provide permanent access, sessions can be hijacked via XSS or MITM attacks, and users cannot securely terminate their sessions.
- **Representative Findings:** `AUTH-VULN-03`, `AUTH-VULN-04`, `AUTH-VULN-05`, `AUTH-VULN-06`.

### Pattern 3: Transport Layer Security Failure
- **Description:** The application operates over plain HTTP with no TLS/HTTPS encryption and lacks all transport security headers (HSTS, Cache-Control for sensitive endpoints).
- **Code Evidence:**
  - Server startup: Line 72: `app.run(host='0.0.0.0', port=5003)` - no `ssl_context` parameter
  - Live test: `curl -v http://localhost:5003/login` returns no `Strict-Transport-Security` header
  - Docker config: Port mapping `5003:5003` with no TLS termination
- **Implication:** All authentication traffic (credentials, session tokens) transmitted in cleartext, vulnerable to network interception and man-in-the-middle attacks.
- **Representative Findings:** `AUTH-VULN-07`, `AUTH-VULN-08`.

### Pattern 4: Missing Abuse Defense Mechanisms
- **Description:** The authentication endpoints have zero rate limiting, no CAPTCHA, no account lockout, and no logging of failed authentication attempts.
- **Code Evidence:**
  - No rate limiting libraries in requirements.txt
  - Login handler (lines 20-35) has no rate limit decorators or attempt tracking
  - Practical test: 50+ consecutive failed login attempts processed without throttling
- **Implication:** Attackers can perform unlimited brute-force attacks, credential stuffing, and password spraying without any defensive response.
- **Representative Findings:** `AUTH-VULN-09`.

### Pattern 5: Plaintext Credential Storage and Weak Password Policy
- **Description:** User credentials are hardcoded in the application source code and stored in plaintext with no password hashing. Additionally, extremely weak passwords are accepted.
- **Code Evidence:**
  - Lines 9-12: `users = {"user": {"password": "user", "role": "user"}, "admin": {"password": "AdmAQ#DCFQ", "role": "admin"}}`
  - Line 26: Direct plaintext comparison: `users[username]['password'] == password`
- **Implication:** Source code exposure = credential compromise. The admin password `AdmAQ#DCFQ` is publicly visible in the repository. User account uses trivially weak password "user".
- **Representative Findings:** `AUTH-VULN-10`, `AUTH-VULN-11`.

## 3. Strategic Intelligence for Exploitation

### Authentication Method
- **Primary mechanism:** JWT-based stateless authentication with session tokens stored in HTTP cookies
- **Token format:** JSON Web Token (JWT) with structure: `base64(header).base64(payload).signature`
- **Actual implementation:** Uses `algorithm='none'` producing tokens with empty signature: `base64(header).base64(payload).`

### Session Token Details
- **Cookie name:** `token`
- **Token structure:** 
  - Header: `{"alg": "none", "typ": "JWT"}`
  - Payload: `{"username": "<username>", "role": "<role>"}`
  - Signature: Empty (no signature due to algorithm='none')
- **Example token (user role):** `eyJhbGciOiJub25lIiwidHlwIjoiSldUIn0.eyJ1c2VybmFtZSI6InVzZXIiLCJyb2xlIjoidXNlciJ9.`
- **Token validation:** Application decodes JWT with `verify_signature: False` at lines 44 and 61
- **Critical detail:** Tokens are 100% deterministic - same username/role always produces identical token

### Password Policy
- **Server-side enforcement:** None - no password complexity validation exists
- **Accepted weak passwords:** "user" (4 characters) accepted for user account
- **Storage mechanism:** Plaintext in-memory dictionary
- **Hardcoded credentials:**
  - Username: `user`, Password: `user`, Role: `user`
  - Username: `admin`, Password: `AdmAQ#DCFQ`, Role: `admin`

### Application Endpoints and Authentication Requirements

| Endpoint | Method | Authentication Required | Authorization Check | Code Location |
|----------|--------|-------------------------|---------------------|---------------|
| `/` | GET | No | N/A | Lines 16-18 (redirects to /login) |
| `/login` | GET | No | N/A | Lines 20-35 (displays login form) |
| `/login` | POST | No | N/A | Lines 20-35 (processes credentials, issues JWT) |
| `/profile` | GET | Yes (JWT cookie) | Role-based conditional rendering | Lines 37-52 (shows admin link for admin role) |
| `/dashboard` | GET | Yes (JWT cookie) | `role == 'admin'` | Lines 54-69 (returns FLAG for admin) |

### Authorization Model
- **Role hierarchy:** `anon` → `user` → `admin`
- **Role storage:** JWT payload field `"role"`
- **Privilege escalation path:** Forge JWT with `"role": "admin"` to access `/dashboard` endpoint and retrieve CTF flag
- **Admin-only resource:** Environment variable `FLAG` accessible only via `/dashboard` endpoint at line 64

### Secret Key Configuration
- **Defined but unused:** Line 14: `SECRET_KEY = 'supersecretkey'`
- **Actually used:** Empty string `''` as signing key at line 27
- **Impact:** The defined SECRET_KEY is never referenced in JWT encoding/decoding

### Network Configuration
- **Protocol:** HTTP only (no HTTPS/TLS)
- **Binding:** `0.0.0.0:5003` (all network interfaces)
- **Reverse proxy:** None - Flask development server directly exposed
- **WSGI server:** Werkzeug 3.0.3 (development server, not production-grade)

## 4. Secure by Design: Validated Components

These components were analyzed and found to have **partial or minimal** defenses. While not exploitable for certain attack vectors, they still fail overall security requirements.

| Component/Flow | Endpoint/File Location | Defense Mechanism Implemented | Verdict |
|---|---|---|---|
| Error Messages (User Enumeration) | POST /login, line 33 | Generic error message: `{"message": "Invalid credentials"}` regardless of whether username exists | **SAFE from enumeration via response content** (but vulnerable to timing attacks) |
| Template Rendering (SSTI) | GET /profile, lines 47 & 49 | Uses `render_template_string()` with hardcoded static templates only - no user input interpolation | **SAFE from SSTI** (but risky coding pattern) |
| CSRF (Login Form) | POST /login | No CSRF tokens exist, but same-origin policy provides partial protection | **VULNERABLE** (no SameSite cookie attribute) |

**Note on "Secure" Components:**
The above components pass specific security checks but exist within an application that has catastrophic authentication failures. These findings indicate areas that do not require immediate exploitation attention, but the overall authentication system is critically broken.