# Authentication Analysis Report

## 1. Executive Summary
- **Analysis Status:** Complete
- **Key Outcome:** Multiple critical authentication flaws were identified, primarily related to weak session management, plaintext password storage, missing transport security, and absent abuse defenses.
- **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: Weak Session Management and Predictable Secret Key
- **Description:** A critical pattern was observed where the Flask session secret key is hardcoded as `'your_secret_key'`. This weak, predictable secret key is the foundation of Flask's session signing mechanism using itsdangerous. With knowledge of this secret (available in the source code), attackers can forge arbitrary session cookies containing any `user_id`, completely bypassing authentication.
- **Implication:** Attackers can impersonate any user in the system by crafting valid session cookies without knowing credentials. This enables horizontal privilege escalation to access any user's account.
- **Representative Findings:** `AUTH-VULN-01` (Session Forgery).

### Pattern 2: Complete Absence of HTTPS/TLS Protection
- **Description:** The application exclusively uses HTTP (port 80) with no HTTPS/TLS configuration at any layer (Flask, Apache, Docker). Session cookies lack the `Secure` flag, allowing transmission over unencrypted HTTP. Combined with missing HSTS headers, credentials and session data are transmitted in plaintext.
- **Implication:** Network attackers can intercept credentials during login and hijack active sessions through Man-in-the-Middle (MITM) attacks, packet sniffing, or WiFi eavesdropping.
- **Representative Findings:** `AUTH-VULN-02` (Session Hijacking via Insecure Transport).

### Pattern 3: Zero Abuse Defenses on Authentication Endpoints
- **Description:** All authentication endpoints lack rate limiting, CAPTCHA, account lockout mechanisms, and failed-login tracking. The login endpoint accepts unlimited attempts without delays, throttling, or human verification. No monitoring or alerting exists for brute force attacks.
- **Implication:** Attackers can perform unlimited brute force attacks, credential stuffing, and password spraying without resistance or detection.
- **Representative Findings:** `AUTH-VULN-03` (Brute Force / Credential Stuffing).

### Pattern 4: Session Fixation and Missing Session Lifecycle Controls
- **Description:** Session IDs are not regenerated after successful login. The logout endpoint uses `session.pop('user_id')` instead of `session.clear()`, leaving potential session residue. No session timeout (PERMANENT_SESSION_LIFETIME) is configured, allowing sessions to persist indefinitely until browser closure.
- **Implication:** Attackers can force victims to use known session IDs (session fixation), hijack those sessions after login, and exploit long-lived sessions on shared computers.
- **Representative Findings:** `AUTH-VULN-04` (Session Fixation).

### Pattern 5: Plaintext Credential Storage (Separate but Related)
- **Description:** While technically a data security issue rather than pure authentication bypass, passwords are stored in plaintext in the database. The authentication query `User.query.filter_by(username=username, password=password).first()` performs direct plaintext comparison. Default credentials (`test:test`) are hardcoded in application initialization.
- **Implication:** Database compromise immediately exposes all credentials. Known default credentials provide instant access. This compounds other authentication vulnerabilities by making credential-based attacks trivial.
- **Note:** This is primarily a credential/data security issue. For pure authentication bypass, focus on session-based attacks (patterns 1-4).

## 3. Strategic Intelligence for Exploitation

### Authentication Method
The system uses Flask's default session-based authentication with client-side signed cookies:
- **Session Library:** Flask's built-in session management using `itsdangerous` for signing
- **Session Storage:** Client-side cookies (not server-side Redis/database sessions)
- **Signing Algorithm:** HMAC-SHA1 or SHA256 (depending on Flask version)
- **Secret Key:** `'your_secret_key'` (hardcoded at `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-104-24/app/website/app/__init__.py:8`)

### Session Token Details
- **Cookie Name:** `session` (Flask default)
- **Cookie Format:** `base64(payload).timestamp.signature`
- **Payload Structure:** `{'user_id': <integer>}`
- **Security Flags:** 
  - `HttpOnly`: True (Flask default) - Prevents JavaScript access
  - `Secure`: False - Allows HTTP transmission (**CRITICAL FLAW**)
  - `SameSite`: None/unset - No CSRF protection
- **Session Creation:** Line 28 of `routes.py`: `session['user_id'] = user.id`
- **Session Validation:** All protected endpoints check `session.get('user_id')`

### Password Policy
- **Storage:** Plaintext in database (`password` column in User model)
- **Comparison:** Direct plaintext comparison in SQLAlchemy query
- **Policy Enforcement:** None (no complexity requirements, length minimums, or validation)
- **Default Credentials:** Username `test`, password `test` (hardcoded in `__init__.py:23-32`)

### Network Architecture
- **Protocol:** HTTP only (port 80 externally via 46413)
- **Web Server:** Apache 2.4.65 with mod_wsgi
- **No TLS:** No SSL/TLS configured at any layer
- **No API Gateway/WAF:** Direct exposure of Flask application

### Authenticated Endpoints Session Validation
All authenticated endpoints properly implement session checks:
- `/home` (GET) - Line 45: `session.get('user_id')`
- `/profile` (GET/POST) - Line 56: `session.get('user_id')`
- `/loan_details` (GET) - Line 79: `session.get('user_id')`
- `/total_loan_payments` (GET) - Line 91: `session.get('user_id')`

**Note:** While session checks are consistently implemented, they are trivially bypassed via session forgery (weak secret key) or session hijacking (no HTTPS).

## 4. Secure by Design: Validated Components

These components were analyzed and found to have robust defenses or correct implementation (though may be undermined by other vulnerabilities):

| Component/Flow | Endpoint/File Location | Defense Mechanism Implemented | Verdict |
|---|---|---|---|
| Session Validation Pattern | All protected endpoints (`routes.py:45,56,79,91`) | Consistent use of `session.get('user_id')` with redirect to login if absent | SAFE (pattern implementation is correct, though underlying session security is weak) |
| Login Error Messages | `routes.py:33` | Generic error message: "Invalid username or password" (prevents user enumeration) | SAFE |
| Session Storage Location | Flask default cookie-based | Sessions not in URLs, only in signed cookies | SAFE (no session IDs in URLs) |
| SQL Injection Protection | All database queries | SQLAlchemy ORM with parameterized queries | SAFE (no SQL injection vectors found) |
| Password Hashing | N/A | NOT IMPLEMENTED (plaintext storage) - Not a "secure component" | VULNERABLE |

**Important Note:** The "SAFE" verdicts above indicate that specific implementation patterns are correct, but do not mean the overall authentication system is secure. The weak secret key and missing HTTPS undermine all session-based security.

---

# 5. Detailed Vulnerability Analysis

## AUTH-VULN-01: Session Forgery via Weak Secret Key

**Vulnerability Type:** Token_Management_Issue / Session_Management_Flaw

**Affected Endpoints:** All authenticated endpoints (session-based auth system-wide)

**Root Cause Location:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-104-24/app/website/app/__init__.py:8`
```python
app.secret_key = 'your_secret_key'  # Change this to a secure secret key
```

**Vulnerability Description:**
Flask uses the `secret_key` to sign session cookies with HMAC. The hardcoded, predictable value `'your_secret_key'` has minimal entropy (15 ASCII characters, ~70 bits maximum). With knowledge of this secret (available in source code), attackers can use Python's `itsdangerous` library to forge arbitrary session cookies containing any `user_id` value, completely bypassing authentication.

**Technical Details:**
- Flask session format: `base64(payload).timestamp.hmac_signature`
- Payload: `{'user_id': <target_user_id>}`
- The signature is computed as: `HMAC-SHA1(secret_key, base64_payload + timestamp)`
- With known secret key, attackers can compute valid signatures for arbitrary payloads

**Exploitation Flow:**
1. Attacker obtains secret key from source code: `'your_secret_key'`
2. Attacker crafts payload: `{'user_id': 1}` (or any target user ID)
3. Attacker uses `itsdangerous.URLSafeTimedSerializer` to sign payload with secret key
4. Attacker sends forged session cookie to application
5. Application validates signature (succeeds because secret key matches)
6. Application extracts `user_id=1` from session and grants access

**Impact:**
- Complete authentication bypass
- Horizontal privilege escalation to any user account
- No credentials required
- Persistent access (forged sessions remain valid until application restart/logout)

**Confidence:** High (deterministic flaw, direct access to secret key in source)

---

## AUTH-VULN-02: Session Hijacking via Insecure Transport

**Vulnerability Type:** Transport_Exposure / Session_Cookie_Misconfig

**Affected Endpoints:** 
- `POST /login` (credential transmission)
- All authenticated endpoints (session cookie transmission)

**Root Cause Locations:**
1. Flask config (`__init__.py:8`): Missing `SESSION_COOKIE_SECURE = True`
2. Apache config (`loan_calculator-httpd.conf:1`): `<VirtualHost *:80>` (HTTP only, no HTTPS)
3. Docker config (`docker-compose.yml:20-21`): Only exposes port 80

**Vulnerability Description:**
The application exclusively uses HTTP with no HTTPS/TLS configured. Session cookies lack the `Secure` flag, allowing transmission over unencrypted HTTP. Login credentials (`username`/`password`) are sent in plaintext POST bodies. No HSTS headers enforce HTTPS.

**Technical Details:**
- `SESSION_COOKIE_SECURE`: Not set (defaults to False)
- Apache VirtualHost: Only `*:80` configured, no `*:443` or SSL directives
- No redirect from HTTP to HTTPS
- No `Strict-Transport-Security` header
- Network traffic is plaintext

**Exploitation Flow:**
1. Attacker positions on network path (WiFi AP, compromised router, ISP-level)
2. Victim logs in via HTTP POST to `/login`
3. Attacker captures plaintext POST body containing username/password
4. Alternatively, attacker captures `Set-Cookie: session=...` header after login
5. Attacker replays captured session cookie to hijack session

**Attack Vectors:**
- Man-in-the-Middle (MITM) on shared WiFi networks
- Packet sniffing with tools like Wireshark
- ARP poisoning on local networks
- BGP hijacking or DNS poisoning at network level

**Impact:**
- Credential theft during login
- Session hijacking of active users
- Persistent unauthorized access

**Confidence:** High (direct evidence of HTTP-only configuration at all layers)

---

## AUTH-VULN-03: Brute Force / Credential Stuffing (No Rate Limiting)

**Vulnerability Type:** Abuse_Defenses_Missing

**Affected Endpoint:** `POST /login`

**Root Cause Location:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-104-24/app/website/app/routes.py:20-34`

**Vulnerability Description:**
The login endpoint has zero protection against automated abuse. No rate limiting, CAPTCHA, account lockout, or failed-login tracking exists. Attackers can send unlimited login attempts per second without delays, throttling, or human verification. No monitoring/alerting exists for attack detection.

**Missing Controls:**
1. **Rate Limiting:** No Flask-Limiter or similar library (checked `requirements.txt`)
2. **Account Lockout:** No failed login counter in User model (`models.py:6-15`)
3. **CAPTCHA:** No reCAPTCHA or hCaptcha in login form (`templates/login.html:17-27`)
4. **Monitoring:** No logging of failed attempts (`routes.py:23-33` has no `logging` calls)
5. **Progressive Backoff:** No delay mechanism for repeated failures

**Code Evidence:**
```python
@app.route('/login', methods=['GET', 'POST'])
def login():
    if request.method == 'POST':
        username = request.form['username']
        password = request.form['password']
        user = User.query.filter_by(username=username, password=password).first()
        if user:
            session['user_id'] = user.id
            return redirect(url_for('home'))
        else:
            return render_template('login.html', error='Invalid username or password')
    return render_template('login.html')
```

No decorators, no rate limiting checks, no attempt counters—every request is processed immediately.

**Exploitation Flow:**
1. Attacker scripts automated login attempts (e.g., using Python requests library)
2. For brute force: Iterate through password list for known username (e.g., `test`)
3. For credential stuffing: Test leaked username:password pairs from breaches
4. For password spraying: Test common passwords across multiple usernames
5. No throttling or blocking occurs; attacker continues indefinitely
6. Success identified by redirect to `/home` instead of error message

**Attack Scalability:**
- Can send 100+ requests/second with simple Python script
- Can test entire rockyou.txt password list (14M passwords) in hours
- No account lockout means same account can be targeted continuously

**Impact:**
- Account takeover through credential guessing
- Credential stuffing using leaked databases
- No detection or alerting of ongoing attacks
- Denial of service through resource exhaustion

**Confidence:** High (complete absence of rate limiting confirmed in code and dependencies)

---

## AUTH-VULN-04: Session Fixation

**Vulnerability Type:** Login_Flow_Logic / Session_Management_Flaw

**Affected Endpoint:** `POST /login`

**Root Cause Location:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-104-24/app/website/app/routes.py:28`

**Vulnerability Description:**
Session IDs are not regenerated after successful authentication. The same session cookie that existed before login remains valid after login with the `user_id` added. Attackers can force victims to use a known session ID before authentication, then hijack that session after the victim logs in.

**Code Evidence:**
```python
user = User.query.filter_by(username=username, password=password).first()
if user:
    session['user_id'] = user.id  # Session ID not regenerated here
    return redirect(url_for('home'))
```

**Missing Control:**
- No `session.regenerate()` call
- No session invalidation before setting new session
- No Flask-Login with session protection

**Exploitation Flow:**
1. Attacker obtains a valid session cookie from the application (e.g., by visiting `/login`)
2. Attacker forces victim to use this session cookie (via XSS, social engineering, or physical access)
3. Victim logs in with their credentials using the attacker-controlled session cookie
4. The session cookie now contains `{'user_id': victim_id}` but keeps the same session ID
5. Attacker uses the same session cookie (which they still have) to access victim's account

**Attack Scenarios:**
- Attacker sends victim a link with session cookie pre-set (if application allows session in URL—not found here)
- Attacker with XSS vulnerability forces victim to use specific session
- Attacker with physical access sets session cookie on shared computer

**Impact:**
- Account hijacking after victim authenticates
- Persistent access to victim's session
- No credentials required after initial fixation

**Confidence:** Medium (direct code evidence, but exploitation requires attacker to force session cookie on victim—moderate setup complexity)

---

## AUTH-VULN-05: Incomplete Session Invalidation on Logout

**Vulnerability Type:** Session_Management_Flaw

**Affected Endpoint:** `GET /logout`

**Root Cause Location:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-104-24/app/website/app/routes.py:39`

**Vulnerability Description:**
The logout endpoint only removes the `user_id` key from the session using `session.pop('user_id', None)` instead of clearing all session data with `session.clear()`. If other session data exists, it persists after logout. The logout also lacks CSRF protection.

**Code Evidence:**
```python
@app.route('/logout')
def logout():
    # Clear user ID from session
    session.pop('user_id', None)  # Only removes user_id key
    return redirect(url_for('login'))
```

**Missing Controls:**
- Should use `session.clear()` to remove all session data
- No CSRF token protection on logout (GET request allows logout CSRF)

**Exploitation Flow (Session Data Residue):**
1. User logs in and session contains `{'user_id': 1, 'custom_data': 'value'}`
2. User logs out; `session.pop('user_id')` removes only `user_id`
3. Session still contains `{'custom_data': 'value'}`
4. If application later checks for presence of other session keys, residual data may cause issues

**Exploitation Flow (Logout CSRF):**
1. Attacker embeds `<img src="http://localhost:46413/logout">` on malicious page
2. Victim visits attacker's page while authenticated to target application
3. Browser automatically sends GET request to `/logout` with victim's session cookie
4. Victim is logged out without consent

**Impact:**
- Potential session data persistence issues (low severity in current implementation as only `user_id` is used)
- Logout CSRF allows attacker to forcibly log out victims (annoyance/DoS)

**Confidence:** Medium (incomplete session cleanup confirmed in code, but current application only uses `user_id` so impact is limited)

---

## AUTH-VULN-06: No Session Timeout Configuration

**Vulnerability Type:** Session_Management_Flaw

**Affected Configuration:** Flask session settings

**Root Cause Location:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-104-24/app/website/app/__init__.py:1-37`

**Vulnerability Description:**
No `PERMANENT_SESSION_LIFETIME` or explicit session timeout is configured. Flask defaults to non-permanent sessions that last until browser closure, but no idle timeout or absolute maximum session lifetime exists. Sessions remain valid indefinitely as long as the browser stays open.

**Missing Configuration:**
```python
# Should be configured but is absent:
app.config['PERMANENT_SESSION_LIFETIME'] = timedelta(minutes=30)
app.config['SESSION_PERMANENT'] = True
```

**Exploitation Flow:**
1. Attacker obtains valid session cookie (via hijacking, forgery, or physical access)
2. Session remains valid indefinitely (or until browser closure)
3. Attacker can use session hours or days after initial compromise
4. On shared computers, sessions persist across users if browser isn't closed

**Impact:**
- Extended window for session hijacking exploitation
- Sessions on shared/public computers remain active after user walks away
- Stolen session cookies remain valid for extended periods

**Confidence:** High (configuration absence confirmed in code)

---

## AUTH-VULN-07: Broken Cache-Control Headers on Authentication Responses

**Vulnerability Type:** Transport_Exposure

**Affected Endpoints:** All endpoints (especially `/login`, `/logout`, `/profile`)

**Root Cause Location:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-104-24/app/website/app/routes.py:8-14`

**Vulnerability Description:**
The `add_header` function intended to set `Cache-Control: no-store` on all responses is fundamentally broken. It attempts to modify immutable request headers instead of response headers and has contradictory cache directives.

**Code Evidence:**
```python
@app.after_request
def add_header(request):  # Wrong parameter name (should be 'response')
    request.headers['Cache-Control'] = 'no-cache, no-store, must-revalidate'  # Can't modify request headers
    request.headers['Pragma'] = 'no-cache'
    request.headers['Expires'] = '0'
    request.headers['Cache-Control'] = 'public, max-age=0'  # Contradicts line 10
    return request  # Should return response
```

**Issues:**
1. Parameter named `request` instead of `response`
2. Attempting to modify immutable `request.headers` (raises TypeError)
3. Line 13 overwrites line 10's secure setting with insecure `public` directive
4. Returns `request` instead of `response`

**Result:** No cache headers are set on any responses. Authentication pages, error messages, and session data may be cached by browsers/proxies.

**Impact:**
- Login pages with error messages cached by browsers
- Shared computers may expose cached authentication pages
- Proxy servers may cache sensitive authentication responses
- Browser "back button" may display cached authenticated pages after logout

**Confidence:** High (broken code confirmed via static analysis)

---

## AUTH-VULN-08: Missing SameSite Cookie Attribute

**Vulnerability Type:** Session_Cookie_Misconfig

**Affected Component:** Flask session cookie configuration

**Root Cause Location:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-104-24/app/website/app/__init__.py:8` (missing config)

**Vulnerability Description:**
The `SESSION_COOKIE_SAMESITE` configuration is not set, defaulting to `None` (older Flask) or `Lax` (newer Flask). Without explicit `Strict` or `Lax` configuration, session cookies may be sent in cross-site requests, enabling CSRF attacks when combined with missing CSRF tokens.

**Missing Configuration:**
```python
# Should be configured but is absent:
app.config['SESSION_COOKIE_SAMESITE'] = 'Lax'  # or 'Strict'
```

**Exploitation Flow (CSRF):**
1. Victim is authenticated to application
2. Attacker hosts malicious page with form: `<form action="http://localhost:46413/profile" method="POST">...</form>`
3. Victim visits attacker's page
4. Browser submits form to `/profile` with victim's session cookie attached
5. Application processes request as if victim initiated it

**Impact:**
- Cross-Site Request Forgery (CSRF) on state-changing operations
- Attacker can trigger profile updates, logouts, or other actions
- Combined with POST `/profile` endpoint lacking CSRF tokens, enables unauthorized data modification

**Confidence:** Medium (configuration absence confirmed, but exploitation requires CSRF attack setup and there's no explicit CSRF token validation found, but also no signup/password change endpoints to make CSRF critical)

---

## AUTH-VULN-09: Default Hardcoded Credentials

**Vulnerability Type:** Weak_Credentials

**Affected Endpoint:** `POST /login`

**Root Cause Location:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-104-24/app/website/app/__init__.py:23-32`

**Vulnerability Description:**
Default credentials `test:test` are hardcoded in application initialization. These credentials are created automatically when the application starts and are publicly known from the source code.

**Code Evidence:**
```python
test = User(
    username='test',
    password='test',
    name='John',
    lastname='Doe',
    email='john@example.com',
    loan_amount=10000.0,
    loan_term_months=60,
    monthly_payment=212.47
)
db.session.add(test)
db.session.commit()
```

**Exploitation Flow:**
1. Attacker navigates to `http://localhost:46413/login`
2. Attacker enters username: `test`, password: `test`
3. Application authenticates successfully
4. Attacker gains full access to test account and application functionality

**Impact:**
- Immediate authenticated access without credential discovery
- Known credentials enable rapid exploitation of other vulnerabilities (e.g., SSTI at `/total_loan_payments`)
- No brute force or credential guessing required

**Confidence:** High (hardcoded credentials confirmed in source code and auto-created on app initialization)

**Note:** While this is a credential security issue rather than a pure authentication bypass mechanism, it provides the easiest path to authenticated access for exploitation of session-based vulnerabilities.

---

# 6. Risk Prioritization Matrix

| Vuln ID | Vulnerability Name | Severity | Exploitability | External Exploitability | Recommended Priority |
|---------|-------------------|----------|----------------|-------------------------|----------------------|
| AUTH-VULN-01 | Session Forgery via Weak Secret Key | CRITICAL | High | Yes | P0 |
| AUTH-VULN-02 | Session Hijacking via Insecure Transport | CRITICAL | High | Yes | P0 |
| AUTH-VULN-03 | Brute Force / Credential Stuffing | HIGH | High | Yes | P1 |
| AUTH-VULN-09 | Default Hardcoded Credentials | HIGH | High | Yes | P1 |
| AUTH-VULN-04 | Session Fixation | MEDIUM | Medium | Yes | P2 |
| AUTH-VULN-06 | No Session Timeout Configuration | MEDIUM | Medium | Yes | P2 |
| AUTH-VULN-07 | Broken Cache-Control Headers | MEDIUM | Low | Yes | P2 |
| AUTH-VULN-05 | Incomplete Session Invalidation on Logout | LOW | Low | Yes | P3 |
| AUTH-VULN-08 | Missing SameSite Cookie Attribute | LOW | Medium | Yes | P3 |

**Priority Definitions:**
- **P0 (Critical):** Immediate exploitation enables complete authentication bypass or credential theft
- **P1 (High):** Enables account takeover with moderate effort or provides direct access
- **P2 (Medium):** Contributes to attack chains or provides limited unauthorized access
- **P3 (Low):** Edge cases or requires significant preconditions

---

# 7. Exploitation Roadmap for Next Phase

## Recommended Exploitation Order:

### Phase 1: Direct Access (Easiest Path)
1. **AUTH-VULN-09:** Use default credentials `test:test` to gain immediate authenticated access
   - This provides baseline access for testing other authenticated vulnerabilities
   - No special tools required

### Phase 2: Session-Based Attacks (Primary Authentication Bypass)
2. **AUTH-VULN-01:** Forge session cookies using weak secret key
   - Demonstrate horizontal privilege escalation to any user ID
   - Proof of Concept: Use Python's `itsdangerous` to craft forged sessions

3. **AUTH-VULN-02:** Capture session cookies via network sniffing
   - Set up MITM environment to intercept HTTP traffic
   - Demonstrate credential and session hijacking

### Phase 3: Automated Abuse
4. **AUTH-VULN-03:** Execute brute force attack on login endpoint
   - Test 1000+ login attempts to demonstrate no rate limiting
   - Show credential stuffing feasibility

### Phase 4: Session Lifecycle Attacks
5. **AUTH-VULN-04:** Demonstrate session fixation attack
   - Requires controlled environment to force session cookie on victim
   - Lower priority due to setup complexity

---

# 8. Remediation Guidance for Defenders

## Critical Fixes (Implement Immediately):

1. **Generate Cryptographically Random Secret Key:**
   ```python
   import os
   app.secret_key = os.urandom(32).hex()  # 256-bit random key
   ```
   Store in environment variable, not source code.

2. **Enable HTTPS/TLS:**
   - Configure Apache SSL/TLS with valid certificate
   - Redirect all HTTP to HTTPS
   - Set `SESSION_COOKIE_SECURE = True`
   - Add HSTS header: `Strict-Transport-Security: max-age=31536000; includeSubDomains`

3. **Implement Password Hashing:**
   ```python
   from werkzeug.security import generate_password_hash, check_password_hash
   # On registration/password change:
   user.password = generate_password_hash(password)
   # On login:
   if check_password_hash(user.password, password):
       # Success
   ```

4. **Add Rate Limiting:**
   ```python
   from flask_limiter import Limiter
   limiter = Limiter(app, key_func=get_remote_address)
   @app.route('/login', methods=['POST'])
   @limiter.limit("5 per minute")
   def login():
       ...
   ```

## High Priority Fixes:

5. **Regenerate Session on Login:**
   ```python
   if user:
       session.clear()  # Clear old session
       session['user_id'] = user.id
       session.modified = True
   ```

6. **Configure Session Timeout:**
   ```python
   from datetime import timedelta
   app.config['PERMANENT_SESSION_LIFETIME'] = timedelta(minutes=30)
   app.config['SESSION_PERMANENT'] = True
   ```

7. **Fix Cache-Control Headers:**
   ```python
   @app.after_request
   def add_header(response):  # Correct parameter
       response.headers['Cache-Control'] = 'no-store, no-cache, must-revalidate'
       response.headers['Pragma'] = 'no-cache'
       response.headers['Expires'] = '0'
       return response
   ```

8. **Set SameSite Cookie Attribute:**
   ```python
   app.config['SESSION_COOKIE_SAMESITE'] = 'Lax'
   ```

9. **Remove Default Credentials:**
   - Delete auto-creation of test user in `__init__.py`
   - Implement proper user registration flow

## Medium Priority Fixes:

10. **Use session.clear() on Logout:**
    ```python
    @app.route('/logout')
    def logout():
        session.clear()  # Clear all session data
        return redirect(url_for('login'))
    ```

---

# 9. Testing Notes for Exploitation Phase

## Session Forgery (AUTH-VULN-01)
**Tools Required:**
- Python with Flask and itsdangerous installed
- Known secret key: `'your_secret_key'`

**Proof of Concept Script:**
```python
from flask import Flask
from flask.sessions import SecureCookieSessionInterface

app = Flask(__name__)
app.secret_key = 'your_secret_key'

session_serializer = SecureCookieSessionInterface().get_signing_serializer(app)
forged_session = session_serializer.dumps({'user_id': 1})
print(f"Forged session cookie: {forged_session}")
```

**Testing Steps:**
1. Run PoC script to generate forged session cookie
2. Use browser developer tools or curl to set session cookie
3. Navigate to authenticated endpoint (e.g., `/home`)
4. Verify access granted without login

## Session Hijacking (AUTH-VULN-02)
**Tools Required:**
- Wireshark or tcpdump for packet capture
- Network position (local network access)

**Testing Steps:**
1. Set up packet capture on network interface
2. Victim logs in via HTTP
3. Capture POST request to `/login` containing plaintext credentials
4. Capture `Set-Cookie` response header with session cookie
5. Replay session cookie in attacker browser
6. Verify access to victim's account

## Brute Force (AUTH-VULN-03)
**Tools Required:**
- Python requests library or Burp Suite Intruder

**Proof of Concept Script:**
```python
import requests

url = "http://localhost:46413/login"
username = "test"
passwords = ["test", "password", "123456", "admin", ...]

for password in passwords:
    response = requests.post(url, data={'username': username, 'password': password})
    if '/login' not in response.url:  # Redirect indicates success
        print(f"Success: {password}")
        break
```

**Testing Steps:**
1. Run automated login attempts (recommend 100-1000 attempts)
2. Verify no rate limiting or blocking occurs
3. Confirm successful authentication with correct password

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**End of Authentication Analysis Report**