# Authentication Analysis Report

## 1. Executive Summary

- **Analysis Status:** Complete
- **Key Outcome:** Critical authentication flaws were identified that enable complete authentication bypass through insecure token generation. The application uses Base64 encoding instead of cryptographically signed tokens, allowing attackers to forge authentication tokens for any user account without credentials.
- **Purpose of this Document:** This report provides the strategic context on the application's authentication mechanisms, dominant flaw patterns, and key architectural details necessary to effectively exploit the vulnerabilities listed in the exploitation queue.

**Critical Findings:**
- **Authentication Bypass via Token Forgery:** Tokens are simple Base64-encoded company IDs with no cryptographic signature
- **Missing Transport Security:** Application runs on HTTP without TLS/SSL, exposing all traffic to interception
- **No Rate Limiting:** Unlimited brute-force attempts possible on authentication endpoints
- **Insecure Session Management:** Missing Secure and SameSite cookie flags, no session expiration, no logout functionality
- **Default Credentials:** Three hardcoded accounts with predictable passwords, including one admin account
- **User Enumeration via Timing:** Observable timing differences reveal valid usernames

## 2. Dominant Vulnerability Patterns

### Pattern 1: Broken Token Authentication (CRITICAL)
- **Description:** The most severe vulnerability is the use of non-cryptographic Base64 encoding for authentication tokens. The `create_access_token` function (main.py:40-41) simply encodes the company ID without any signature, expiration, or cryptographic protection. Despite importing python-jose JWT library, the application completely bypasses it in favor of reversible Base64 encoding.
- **Implication:** Attackers can forge valid authentication tokens for any user by simply Base64-encoding the target company ID. No credentials required. Token for company_id=1 is always "MQ==", for company_id=2 is always "Mg==", etc.
- **Representative Findings:** `AUTH-VULN-01` (Token Forgery), `AUTH-VULN-02` (Authentication Bypass)
- **Root Cause:** File `/app/main.py:40-41` - `return base64.b64encode(data.encode()).decode()`
- **Attack Complexity:** Trivial - requires only basic Base64 knowledge

### Pattern 2: Missing Transport Layer Security (HIGH)
- **Description:** The application operates exclusively over unencrypted HTTP with no HTTPS/TLS configuration. Authentication cookies lack the Secure flag and are transmitted in plaintext. No HSTS headers enforce secure connections.
- **Implication:** All authentication traffic including credentials and session tokens can be intercepted by network attackers via man-in-the-middle attacks on shared networks.
- **Representative Findings:** `AUTH-VULN-03` (Missing HTTPS), `AUTH-VULN-04` (Insecure Cookie Transmission), `AUTH-VULN-05` (Missing Cache-Control Headers)
- **Root Cause:** Dockerfile line 14 configures Uvicorn on port 80 (HTTP only), cookie set at main.py:96 without `secure=True` flag

### Pattern 3: Absent Authentication Abuse Defenses (HIGH)
- **Description:** The application lacks fundamental protections against authentication abuse: no rate limiting on any endpoint, no account lockout mechanism, no CAPTCHA, no monitoring of failed attempts. Attackers can perform unlimited login attempts without restriction.
- **Implication:** Enables credential stuffing, password spraying, and denial-of-service attacks against authentication endpoints. Combined with weak default passwords, this creates a direct attack path.
- **Representative Findings:** `AUTH-VULN-06` (No Rate Limiting), `AUTH-VULN-07` (No Account Lockout), `AUTH-VULN-09` (User Enumeration via Timing)
- **Root Cause:** No rate limiting middleware configured, no failed attempt tracking in database schema

### Pattern 4: Flawed Session Management (HIGH)
- **Description:** Session management violates multiple security best practices: no session ID rotation after login (tokens are deterministic), no logout functionality, no server-side session invalidation, missing SameSite cookie attribute (CSRF vulnerable), and tokens never expire despite ACCESS_TOKEN_EXPIRE_MINUTES constant being defined.
- **Implication:** Stolen tokens remain valid indefinitely, session fixation attacks possible, CSRF attacks enabled, and users cannot terminate their sessions.
- **Representative Findings:** `AUTH-VULN-10` (No Session Rotation), `AUTH-VULN-11` (No Logout Functionality), `AUTH-VULN-12` (Missing SameSite Flag), `AUTH-VULN-13` (No Token Expiration)
- **Root Cause:** Deterministic token generation, no session storage mechanism, cookie configuration missing security attributes

### Pattern 5: Weak Credential Management (MEDIUM)
- **Description:** The application contains hardcoded default credentials for three accounts (including one admin) that are recreated on every startup. No password complexity policy is enforced. Timing attacks enable username enumeration.
- **Implication:** Default credentials provide guaranteed access (demo/demo, company2/ajsdasd987asd87as7da9, company3/password3). Weak passwords like "demo" are accepted. Admin account "company2" provides privileged access to flag data.
- **Representative Findings:** `AUTH-VULN-08` (Default Credentials), `AUTH-VULN-14` (Weak Password Policy), `AUTH-VULN-09` (User Enumeration)
- **Root Cause:** Startup handler (main.py:58-62) hardcodes credentials, no password validation in schemas

## 3. Strategic Intelligence for Exploitation

### Authentication Method
The system uses a custom token-based authentication that superficially resembles JWT but is fundamentally insecure:
- **Token Format:** `Bearer <base64_encoded_company_id>`
- **Token Generation:** `base64.b64encode(str(company_id).encode()).decode()`
- **Token Validation:** Simple Base64 decode and comparison with URL parameter
- **No Cryptographic Signature:** Tokens lack integrity protection
- **Deterministic Generation:** Same input always produces same token

### Session Token Details
- **Cookie Name:** `access_token`
- **Cookie Value Format:** `Bearer MQ==` (example for company_id=1)
- **Cookie Flags Configured:** `httponly=True` only
- **Missing Cookie Flags:** `secure`, `samesite`, `max_age`/`expires`
- **Token Never Expires:** Despite ACCESS_TOKEN_EXPIRE_MINUTES=30 constant, expiration is not enforced
- **No Server-Side Storage:** Tokens are stateless with no session tracking mechanism

### Token Forgery Attack Path
1. Identify target company_id (sequential: 1, 2, 3, or enumerate)
2. Generate forged token: `echo -n "2" | base64` → `Mg==`
3. Set cookie: `access_token=Bearer Mg==`
4. Access any endpoint as that user: `GET /company/2/jobs`
5. Token validation passes because it only checks decoded value matches URL parameter

### Default Credentials (High-Value Targets)
| Username | Password | Admin Status | Company ID |
|----------|----------|--------------|------------|
| demo | demo | No | 1 |
| company2 | ajsdasd987asd87as7da9 | **Yes (Admin)** | 2 |
| company3 | password3 | No | 3 |

**Note:** Admin account "company2" can access private jobs containing the flag (line 77 in main.py).

### Password Policy Weaknesses
- **Minimum Length:** None enforced (4-char passwords accepted)
- **Complexity Requirements:** None
- **Common Password Check:** None
- **Hashing Algorithm:** Bcrypt (secure, but irrelevant given token forgery)

### Timing Attack for User Enumeration
- **Non-existent user:** ~1ms response (immediate return)
- **Existing user + wrong password:** ~100-300ms (bcrypt verification)
- **Exploit:** Measure response times to build list of valid usernames
- **Attack Location:** POST /token endpoint, authenticate_company function (main.py:44-50)

### Network Security Posture
- **Protocol:** HTTP only (port 80)
- **TLS/SSL:** Not configured
- **HSTS:** Not configured
- **Reverse Proxy:** None (Uvicorn exposed directly)
- **Security Headers:** None configured
- **Result:** All traffic transmitted in cleartext

### Rate Limiting Status
- **Login Endpoint (POST /token):** No rate limiting
- **Profile Update (POST /edit_profile):** No rate limiting
- **Account Lockout:** Not implemented
- **CAPTCHA:** Not implemented
- **Monitoring:** No failed login tracking or alerting

## 4. Secure by Design: Validated Components

These components were analyzed and found to have robust defenses. They are low-priority for further testing.

| Component/Flow | Endpoint/File Location | Defense Mechanism Implemented | Verdict |
|---|---|---|---|
| Password Hashing | `/app/crud.py:18` | Uses bcrypt via passlib with CryptContext configuration | SAFE |
| Password Verification | `/app/main.py:36-37` | Timing-safe bcrypt comparison via pwd_context.verify() | SAFE |
| SQL Injection Protection | All CRUD operations in `/app/crud.py` | SQLAlchemy ORM with parameterized queries throughout | SAFE |
| XSS Protection | All templates in `/app/templates/` | Jinja2 autoescape enabled by default, no unsafe filters used | SAFE |
| Input Type Validation | All endpoints in `/app/main.py` | FastAPI automatic validation via Pydantic schemas and type hints | SAFE |

**Note on Secure Components:** While the password storage mechanism uses industry-standard bcrypt hashing, this defense is rendered largely academic by the token forgery vulnerability which allows complete authentication bypass without needing to crack passwords. Similarly, SQL injection protection via SQLAlchemy ORM is properly implemented but irrelevant when attackers can forge tokens to access any account's data through legitimate application code paths.

## 5. Code-Level Vulnerability Details

### Critical Code Locations

**Token Generation (CRITICAL FLAW):**
```python
# File: /app/main.py
# Line: 40-41
def create_access_token(data: str):
    return base64.b64encode(data.encode()).decode()
```
**Issue:** No cryptographic signature, just reversible encoding.

**Token Validation (INEFFECTIVE):**
```python
# File: /app/main.py
# Lines: 131-149
async def validate_token(company_id, request):
    token = request.cookies.get("access_token")
    if not token:
        raise credentials_exception
    try:
        token_company_id = int(base64.b64decode(token.split(" ")[1]).decode())
        if token_company_id != company_id:
            raise credentials_exception
    except JWTError:  # Dead code - never raised
        raise credentials_exception
```
**Issue:** Only validates format and matches URL parameter, no signature verification.

**Cookie Configuration (INSECURE):**
```python
# File: /app/main.py
# Line: 96
response.set_cookie(key="access_token", value=f"Bearer {access_token}", httponly=True)
```
**Issue:** Missing `secure=True` and `samesite="Lax"` flags.

**Default Credentials (HIGH RISK):**
```python
# File: /app/main.py
# Lines: 58-62
example_companies = [
    {"name": "demo", "password": "demo", "is_admin": False},
    {"name": "company2", "password": "ajsdasd987asd87as7da9", "is_admin": True},
    {"name": "company3", "password": "password3", "is_admin": False}
]
```
**Issue:** Hardcoded credentials including admin account.

**User Enumeration (TIMING ATTACK):**
```python
# File: /app/main.py
# Lines: 44-50
def authenticate_company(db, name: str, password: str):
    company = crud.get_company_by_name(db, name)
    if not company:
        return False  # Fast path: ~1ms
    if not verify_password(password, company.hashed_password):
        return False  # Slow path: ~100-300ms (bcrypt)
    return company
```
**Issue:** Observable timing difference reveals valid usernames.

**No Rate Limiting Middleware:**
```python
# File: /app/main.py
# Line: 21
app = FastAPI()  # No middleware configured
```
**Issue:** No app.add_middleware() calls for rate limiting or security headers.

**Transport Security (PRODUCTION RISK):**
```dockerfile
# File: /app/Dockerfile
# Line: 14
CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "80", "--reload"]
```
**Issue:** HTTP only (port 80), no SSL configuration, --reload flag in production.

## 6. Architecture Notes for Exploitation

### Authentication Flow
1. User submits credentials to POST /token
2. Application calls authenticate_company() → database lookup → bcrypt verification
3. On success, create_access_token(str(company_id)) generates Base64 token
4. Token set as httponly cookie
5. Redirect to /company/{company_id}/jobs

### Authorization Checks
- All authenticated endpoints call `validate_token(company_id, request)` 
- Validation only checks: token exists, can be base64-decoded, decoded value matches URL parameter
- No JWT signature verification, no expiration checking, no server-side session lookup
- Admin privileges checked inline: `if company.is_admin` (line 112)

### No Logout Mechanism
- No logout endpoint exists
- No cookie clearing functionality
- No server-side session invalidation
- Tokens valid indefinitely once issued

### Database Schema Notes
- Companies table: id, name, hashed_password, is_admin
- No sessions table, no tokens table, no tracking of active sessions
- Completely stateless authentication with no revocation capability

### Exploitation Dependencies
- **Network Access:** Application accessible at http://localhost:38803/
- **Tools Required:** curl, base64 encoding capability, or any HTTP client
- **Credentials Required:** NONE (token forgery bypasses authentication)
- **Alternative:** Default credentials demo/demo or company2/ajsdasd987asd87as7da9

---

*Analysis completed with systematic verification of all authentication endpoints, session management mechanisms, and credential handling workflows.*