# Authentication Analysis Report

## 1. Executive Summary
- **Analysis Status:** Complete
- **Key Outcome:** Multiple critical authentication flaws were identified, including complete absence of session management, no transport security, missing rate limiting, and hardcoded default credentials. The application's authentication model is fundamentally broken.
- **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 Session Management
- **Description:** The application has NO session management whatsoever. After login, users are redirected to `/profile/${user._id}` with the MongoDB ObjectId in the URL, which becomes the only "authentication" mechanism. No session cookies, no JWT tokens, and no authentication state is created or maintained.
- **Implication:** Any user can access any profile by directly navigating to `/profile/{objectid}`. The URL itself is the authentication, enabling trivial IDOR attacks and complete authentication bypass.
- **Representative Findings:** `AUTH-VULN-01`, `AUTH-VULN-02`, `AUTH-VULN-06`.

### Pattern 2: Missing Abuse Defenses (Rate Limiting, CAPTCHA, Account Lockout)
- **Description:** The application lacks ALL defenses against automated attacks. No rate limiting on any endpoint, no CAPTCHA on registration or login, no account lockout after failed attempts, and no monitoring or alerting.
- **Implication:** Attackers can perform unlimited brute force attacks, credential stuffing, password spraying, and automated account creation without any throttling or detection.
- **Representative Finding:** `AUTH-VULN-03`.

### Pattern 3: Transport Layer Insecurity
- **Description:** The application runs over plain HTTP with no HTTPS/TLS configuration. No HSTS headers, no secure transport enforcement, and credentials transmitted in plaintext.
- **Implication:** All authentication traffic (passwords, session data, user IDs) is vulnerable to man-in-the-middle attacks and network interception.
- **Representative Finding:** `AUTH-VULN-04`.

### Pattern 4: Information Disclosure Enabling Attacks
- **Description:** Multiple endpoints disclose sensitive system information including MongoDB ObjectIds, user counts, ObjectId counter distances, and precise application start timestamps.
- **Implication:** This information enables ObjectId prediction attacks, allowing attackers to calculate the first user's ObjectId and access their profile to retrieve the flag without authentication.
- **Representative Finding:** `AUTH-VULN-05`.

## 3. Strategic Intelligence for Exploitation

### Authentication Method
The system uses bcrypt-based password verification (cost factor 10) but creates NO persistent authentication state. After successful login, the application redirects to `/profile/${user._id}` where the MongoDB ObjectId in the URL becomes the sole access control mechanism.

### Session Token Details
**NO session tokens exist.** The application has no session management library, no cookies are set for authentication purposes, and no JWT tokens are issued. Authentication state is URL-based only.

### Password Policy
- **NO server-side password policy enforcement**
- Users can register with single-character or empty passwords
- No complexity requirements (no uppercase, lowercase, numbers, or special characters)
- **Hardcoded default credentials exist:** Username `user0`, Password `1b2e97s80wb7d08n-`

### Key Endpoints and Flows
1. **POST /register** (Lines 140-171): Returns `userId` (MongoDB ObjectId) and `distance` (counter difference) in JSON response
2. **POST /login** (Lines 189-200): Validates password with bcrypt but creates no session; redirects to `/profile/${user._id}`
3. **GET /profile/:id** (Lines 202-215): NO authentication check; displays profile for ANY valid ObjectId
4. **GET /starttime** (Lines 226-228): Returns exact Unix timestamp of application start (required for ObjectId prediction)
5. **GET /info** (Lines 217-224): Returns total user count and application start timestamp

### Timing Attack Vector
The login endpoint is vulnerable to timing attacks for username enumeration:
- Invalid username: Fast response (~10-50ms) - no bcrypt operation
- Valid username + wrong password: Slow response (~100-300ms) - bcrypt.compare() executed
- Attackers can distinguish valid from invalid usernames based on response time

### ObjectId Prediction Attack Chain
1. Access `/starttime` → obtain `appStartTimestamp`
2. Register new account → receive `userId` and `distance` in response
3. Calculate first user's ObjectId using timestamp + counter distance
4. Access `/profile/{calculated_objectid}` → retrieve flag without authentication

## 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/server.js:42, 153` | Uses bcrypt with cost factor 10 for password hashing | SAFE |
| Password Verification | `/app/server.js:195` | Uses bcrypt.compare() for constant-time password comparison | SAFE |
| Generic Login Errors | `/app/server.js:193, 197` | Both "user not found" and "wrong password" redirect identically to `/login` | SAFE (but timing attack still possible) |

### Notes on Password Storage
While the application properly uses bcrypt for password hashing, this is the ONLY security control implemented. The bcrypt cost factor of 10 is acceptable but modern recommendations suggest 12-14 for higher security applications.

---

# Detailed Findings by Methodology Check

## 1. Transport & Caching

### HTTPS/TLS Configuration: ABSENT ❌
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-099-24/app/server.js:10-14`
```javascript
const startServer = () => {
    app.listen(PORT, () => {
        console.log(`Server running on http://localhost:${PORT}`);
    });
};
```
- Application uses plain HTTP via `app.listen()` (Line 11)
- No HTTPS/TLS configuration in application code
- No SSL certificates or `https.createServer()`
- Docker configuration (`docker-compose.yml:4-5`) exposes port 3000 over HTTP only
- No reverse proxy for TLS termination

**Verdict:** VULNERABLE - No transport encryption

### HSTS Header: ABSENT ❌
**Evidence:** 
- No security middleware installed (package.json has no `helmet` or similar)
- No manual HSTS header setting in code
- No `Strict-Transport-Security` header in HTTP responses (verified via curl)

**Verdict:** VULNERABLE - No HSTS enforcement

### Cache-Control Headers: ABSENT ❌
**Endpoints Checked:**
- GET /register (Line 88-138): No cache headers
- POST /register (Line 140-171): No cache headers
- GET /login (Line 173-187): No cache headers
- POST /login (Line 189-200): No cache headers  
- GET /profile/:id (Line 202-215): No cache headers

**Evidence:**
- No `Cache-Control`, `Pragma`, or `no-store` headers in responses (verified via curl)
- No caching middleware configured
- Sensitive authentication pages and responses may be cached by browsers/proxies

**Verdict:** VULNERABLE - No cache control, responses may be cached

---

## 2. Rate Limiting / CAPTCHA / Monitoring

### Rate Limiting: ABSENT ❌
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-099-24/app/package.json:12-16`
```json
"dependencies": {
  "bcryptjs": "^2.4.3",
  "express": "^4.19.2",
  "mongoose": "^8.4.1"
}
```
- No rate limiting libraries installed (no `express-rate-limit`, `rate-limiter-flexible`)
- No rate limiting middleware configured (Line 80: only `express.urlencoded` middleware)
- All authentication endpoints allow unlimited requests

**Endpoints Vulnerable:**
- POST /register (Lines 140-171): Unlimited account creation
- POST /login (Lines 189-200): Unlimited login attempts
- GET /profile/:id (Lines 202-215): Unlimited profile enumeration

**Verdict:** VULNERABLE - Brute force attacks possible

### Account Lockout: ABSENT ❌
**User Schema:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-099-24/app/server.js:26-30`
```javascript
const UserSchema = new mongoose.Schema({
    username: String,
    password: String,
    createdAt: { type: Date, default: Date.now },
});
```
- No `failedLoginAttempts` field
- No `lockoutUntil` timestamp
- No account lockout logic in login handler (Lines 189-200)

**Verdict:** VULNERABLE - Unlimited login attempts allowed

### CAPTCHA: ABSENT ❌
**Evidence:**
- No CAPTCHA libraries in package.json
- No CAPTCHA widgets in registration form (Lines 88-138)
- No CAPTCHA widgets in login form (Lines 173-187)
- No CAPTCHA validation in POST handlers

**Verdict:** VULNERABLE - No bot protection

### Monitoring/Logging: MINIMAL (Console Only) ❌
**Logging Analysis:**
- No structured logging libraries (no `winston`, `bunyan`, `pino`)
- Only basic console.log statements for application events
- **Login endpoint (Lines 189-200): NO logging of failed or successful login attempts**
- **Registration endpoint (Lines 140-171): Only generic "Registering new user" message**
- No security event logging, no IP address tracking, no audit trail

**Verdict:** VULNERABLE - No security monitoring

---

## 3. Session Management (Cookies)

### Session Management Library: ABSENT ❌
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-099-24/app/package.json`
- No `express-session`, `cookie-session`, or session store packages
- No JWT libraries (`jsonwebtoken`, `passport-jwt`)
- No authentication middleware (`passport`)

**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-099-24/app/server.js:80`
```javascript
app.use(express.urlencoded({ extended: true }));
```
- Only middleware: `express.urlencoded` for parsing form data
- No session middleware configured

**Verified:** No Set-Cookie headers in HTTP responses (tested via curl)

**Verdict:** VULNERABLE - No session management

### Cookie Security Flags: N/A (No Cookies Used) ⚠️
- No cookies are set by the application
- HttpOnly flag: N/A
- Secure flag: N/A
- SameSite attribute: N/A

**Verdict:** N/A - Authentication state is URL-based, not cookie-based

---

## 4. Token/Session Properties (Entropy, Protection, Expiration & Invalidation)

### Session/Token Entropy: N/A (No Tokens Exist) ⚠️
- No session IDs generated
- No JWT tokens issued
- No custom authentication tokens

**Authentication Mechanism Used:**
```javascript
// Line 199 - Login redirect
res.redirect(`/profile/${user._id}`);
```
The MongoDB ObjectId in the URL becomes the only "authentication" token.

**Verdict:** VULNERABLE - URL-based pseudo-authentication, no proper tokens

### Token/Session Expiration: ABSENT ❌
- No session expiration configuration
- No idle timeout
- No absolute timeout
- Profile URLs remain valid indefinitely (they're just GET endpoints with no authentication check)

**Verdict:** VULNERABLE - No expiration mechanism

### Token/Session Invalidation: ABSENT ❌
- No logout endpoint exists (verified: grep search for "logout" returned 0 matches)
- No session destruction logic (no sessions to invalidate)
- Users cannot terminate their authentication state

**Verdict:** VULNERABLE - No logout functionality

---

## 5. Session Fixation

### Session ID Rotation After Login: ABSENT ❌
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-099-24/app/server.js:189-200`
```javascript
app.post('/login', async (req, res) => {
    const { username, password } = req.body;
    const user = await User.findOne({ username });
    if (!user) {
        return res.redirect('/login');
    }
    const isMatch = await bcrypt.compare(password, user.password);
    if (!isMatch) {
        return res.redirect('/login');
    }
    res.redirect(`/profile/${user._id}`);  // No session creation or rotation
});
```

**Analysis:**
- No pre-login session ID exists
- No post-login session ID created
- No session regeneration logic
- Simply redirects to profile URL without creating authentication state

**Verdict:** N/A - Session fixation is not applicable because no sessions exist

---

## 6. Password & Account Policy

### Default Credentials: PRESENT ❌
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-099-24/app/server.js:37-63`
```javascript
const createInitialUsers = async () => {
    await User.deleteMany({});
    try {
        const username = `user0`;
        const password = "1b2e97s80wb7d08n-";  // HARDCODED
        const hashedPassword = await bcrypt.hash(password, 10);
        
        const user = new User({
            username,
            password: hashedPassword,
            createdAt: new Date(),
        });
        await user.save();
```

**Finding:** Hardcoded default user created on every application start
- Username: `user0`
- Password: `1b2e97s80wb7d08n-`
- Database wiped and user recreated on startup (Line 38)

**Verdict:** VULNERABLE - Hardcoded credentials

### Password Policy Enforcement: ABSENT ❌
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-099-24/app/server.js:140-171`
```javascript
app.post('/register', async (req, res) => {
    // ...
    const { username, password } = req.body;  // Line 152
    const hashedPassword = await bcrypt.hash(password, 10);  // Line 153
    const user = new User({ username, password: hashedPassword });
    await user.save();
```

**Analysis:**
- No minimum password length check
- No maximum password length check
- No complexity requirements (uppercase, lowercase, numbers, special characters)
- No weak password rejection
- Users can register with single-character or empty passwords

**Verdict:** VULNERABLE - No password policy

### Password Storage: SECURE ✅
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-099-24/app/server.js:42, 153, 195`
```javascript
// Hashing (Lines 42, 153)
const hashedPassword = await bcrypt.hash(password, 10);

// Verification (Line 195)
const isMatch = await bcrypt.compare(password, user.password);
```

**Analysis:**
- Algorithm: bcrypt (from bcryptjs v2.4.3)
- Cost factor: 10 (2^10 = 1,024 iterations)
- One-way hashing (not reversibly encrypted)
- Constant-time comparison via bcrypt.compare()

**Verdict:** SAFE - Properly implemented password hashing

### MFA/2FA: ABSENT ❌
**User Schema:** No MFA fields (no TOTP secret, backup codes, phone number)
**Dependencies:** No MFA libraries installed
**Login Flow:** Simple password-only authentication

**Verdict:** VULNERABLE - No multi-factor authentication

---

## 7. Login/Signup Responses (Minimal Logic Checks)

### User Enumeration via Error Messages: SAFE (Response) ✅
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-099-24/app/server.js:189-200`
```javascript
if (!user) {
    return res.redirect('/login');  // Line 193
}
const isMatch = await bcrypt.compare(password, user.password);
if (!isMatch) {
    return res.redirect('/login');  // Line 197
}
```

**Analysis:**
- Both "user not found" (Line 193) and "wrong password" (Line 197) produce identical responses
- Both redirect to `/login` with no distinguishing information
- No explicit user enumeration via error messages

**Verdict:** SAFE - Generic error handling

### User Enumeration via Timing Attack: VULNERABLE ❌
**File:** Same endpoint (Lines 189-200)

**Analysis:**
- **Invalid username:** Database query returns null → Immediate redirect (~10-50ms)
- **Valid username + wrong password:** Database query + bcrypt.compare() → Slow response (~100-300ms)
- bcrypt operations are computationally expensive and create measurable timing difference

**Attack:**
```
POST /login username=nonexistent → Fast response → Username invalid
POST /login username=user0 → Slow response → Username valid (bcrypt executed)
```

**Verdict:** VULNERABLE - Username enumeration via timing side-channel

### Information Disclosure in Registration Response: VULNERABLE ❌
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-099-24/app/server.js:165-170`
```javascript
res.status(200).json({
    userId: user._id,              // MongoDB ObjectId
    userNumber: userNumber,        // User count
    message: `User created successfully. Total users: ${totalUsers}`,
    distance: diff_c               // ObjectId counter difference
});
```

**Disclosed Information:**
1. **userId (Line 166):** Complete MongoDB ObjectId - enables IDOR attacks
2. **userNumber (Line 167):** User count in database
3. **totalUsers (Line 168):** Total users - system enumeration
4. **distance (Line 169):** ObjectId counter difference from first user - enables ObjectId prediction

**Verdict:** VULNERABLE - Critical information disclosure

### Authentication State in URLs: VULNERABLE ❌
**File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-099-24/app/server.js:199`
```javascript
res.redirect(`/profile/${user._id}`);
```

**Issues:**
- User ID (MongoDB ObjectId) exposed in URL
- Visible in browser history, referrer headers, server logs, bookmarks
- URL can be shared or replayed indefinitely
- No session-based authentication, URL is the only access control

**Verdict:** VULNERABLE - Authentication state leaked in URL

---

## 8. Recovery & Logout

### Password Reset/Recovery: ABSENT ❌
**Evidence:**
- Grep search for "reset", "recovery", "forgot", "recover" returned 0 matches
- No password reset endpoints exist
- No email functionality for password recovery
- No reset token generation or validation

**Verdict:** N/A - Feature not implemented

### Logout Endpoint: ABSENT ❌
**Evidence:**
- Grep search for "logout", "signout" returned 0 matches
- No `/logout` endpoint exists
- No logout button in HTML pages
- No session destruction logic (consistent with no session management)

**Verdict:** VULNERABLE - Users cannot logout

---

## 9. SSO/OAuth

### OAuth/OIDC Implementation: N/A ⚠️
The application does not implement SSO, OAuth, or OIDC flows.

**Verdict:** N/A - Feature not implemented

---

# Summary of Findings

## Critical Vulnerabilities (Externally Exploitable)

| ID | Vulnerability Type | Severity | Location | Externally Exploitable |
|---|---|---|---|---|
| AUTH-VULN-01 | No Session Management | CRITICAL | server.js:189-200, 202-215 | YES |
| AUTH-VULN-02 | URL-Based Authentication (IDOR) | CRITICAL | server.js:199, 202-215 | YES |
| AUTH-VULN-03 | No Rate Limiting / Account Lockout | HIGH | server.js:140-171, 189-200 | YES |
| AUTH-VULN-04 | No HTTPS/TLS Transport Encryption | CRITICAL | server.js:10-14, docker-compose.yml | YES |
| AUTH-VULN-05 | Information Disclosure (ObjectId, Timestamps) | HIGH | server.js:165-170, 226-228 | YES |
| AUTH-VULN-06 | No Session Expiration/Logout | HIGH | Entire application | YES |
| AUTH-VULN-07 | Hardcoded Default Credentials | HIGH | server.js:37-63 | YES |
| AUTH-VULN-08 | No Password Policy | MEDIUM | server.js:140-171 | YES |
| AUTH-VULN-09 | Timing Attack (Username Enumeration) | MEDIUM | server.js:189-200 | YES |
| AUTH-VULN-10 | No Cache-Control Headers | MEDIUM | All auth endpoints | YES |

## Secure Components

| Component | Security Control | Verdict |
|---|---|---|
| Password Hashing | bcrypt with cost factor 10 | SAFE |
| Password Verification | bcrypt.compare() constant-time | SAFE |
| Login Error Messages | Generic redirects (but timing attack exists) | SAFE |

---

**Analysis Complete**