# Authorization Analysis Report

## 1. Executive Summary

- **Analysis Status:** Complete  
- **Key Outcome:** One CRITICAL horizontal privilege escalation vulnerability identified. The application suffers from a session fixation flaw that allows attackers to authenticate with valid credentials but set an arbitrary user_id in their session, enabling complete account takeover of any user including the flag user (ID 10001).
- **Vertical Escalation:** NOT APPLICABLE - No role-based access control system exists; all authenticated users have identical privileges.
- **Context-Based Escalation:** NOT APPLICABLE - No multi-step workflows or state-based operations exist in the application.
- **Purpose of this Document:** This report provides the strategic context, vulnerability details, and architectural intelligence necessary to effectively exploit the authorization vulnerability listed in the machine-readable exploitation queue (authz_exploitation_queue.json).

---

## 2. Dominant Vulnerability Patterns

### Pattern 1: Client-Controlled Session Identity (Horizontal Privilege Escalation)
- **Description:** The authentication endpoint accepts a client-controlled `user_id` parameter from a hidden form field and directly assigns it to the user's session without validating that the authenticated user matches this ID
- **Implication:** An attacker can authenticate with known credentials (test:test) but manipulate the hidden `user_id` field to assume any other user's identity, including the flag user (ID 10001), completely bypassing password authentication for the target account
- **Representative:** AUTHZ-VULN-01
- **CWE:** CWE-639 (Authorization Bypass Through User-Controlled Key)
- **Root Cause Location:** routes.py:55-56
- **Exploitation Complexity:** TRIVIAL - Requires only browser DevTools or HTTP proxy to modify hidden form field
- **Impact:** Complete account takeover, unauthorized access to sensitive data (flag extraction from user 10001's last_name field)

---

## 3. Strategic Intelligence for Exploitation

### Session Management Architecture:
- **Session Type:** Flask client-side signed cookies using `app.secret_key` for HMAC signature
- **Secret Key:** Hardcoded as `'your_secret_key'` (__init__.py:11) - weak and publicly known
- **Session Structure:** Contains single value: `session['user_id'] = <integer>`
- **Session Creation:** Occurs at routes.py:56 after password validation
- **Critical Finding:** Session user_id is populated from `request.form['user_id']` (client-controlled) rather than from the authenticated user object's ID
- **Session Validation:** Dashboard only checks if `session.get('user_id')` exists, never re-validates ownership
- **No Session Re-authentication:** Once created, sessions are never cross-checked against the original authenticated user

### Role/Permission Model:
- **NO ROLE SYSTEM EXISTS** - User model contains zero role, permission, or privilege fields
- **User Model Fields:** id, username, password, first_name, last_name, email (6 fields total, no RBAC)
- **Privilege Levels:** Simple binary - anonymous vs authenticated (no admin/user hierarchy)
- **All Authenticated Users Are Equivalent:** test user and flag user have identical access rights
- **Critical Finding:** Vertical privilege escalation is not applicable because no elevated privileges exist

### Resource Access Patterns:
- **Dashboard Endpoint:** `/dashboard` accepts no parameters, retrieves user data based solely on `session['user_id']`
- **No IDOR Surface:** Dashboard doesn't accept user_id in URL/query parameters (e.g., /dashboard?user_id=X)
- **Data Exposure:** Dashboard renders `user.first_name` and `user.last_name` for the session user
- **Flag Storage:** User ID 10001 has last_name field containing the flag value (loaded from /flag file at startup)
- **Critical Finding:** Dashboard trusts session integrity completely; exploitation requires compromising session creation

### Authentication Flow & Vulnerability Chain:
1. **Stage 1 - Username Validation** (routes.py:19-32):
   - User submits username
   - Server validates username exists in database
   - Server redirects to `/password/<username>`
   
2. **Stage 2 - Password Form Rendering** (routes.py:44-50):
   - Server renders password.html template
   - Template includes hidden fields: `username` and `user_id` (password.html:28-29)
   - **CRITICAL:** `user_id` value is exposed to client, modifiable via DevTools/proxy
   
3. **Stage 3 - Password Validation** (routes.py:51-57):
   - Server validates `username` + `password` combination (line 53)
   - If valid: user object retrieved for authenticated username
   - **VULNERABILITY:** Server checks if `request.form['user_id']` exists in database (line 55)
   - **VULNERABILITY:** Server sets `session['user_id'] = request.form['user_id']` (line 56)
   - **MISSING CHECK:** No validation that `request.form['user_id'] == user.id`
   
4. **Stage 4 - Dashboard Access** (routes.py:69-78):
   - Dashboard retrieves `user_id = session.get('user_id')`
   - Queries database: `User.query.get(user_id)`
   - Renders data for whatever user_id is in session (no ownership validation)

### Known User Accounts:
- **Test Account:** username='test', password='test', id=10032 (credentials known/public)
- **Flag Account:** username='flag', password={100-char random string}, id=10001, last_name={FLAG}
- **Attack Vector:** Authenticate as test user, manipulate user_id to 10001, access flag user's dashboard

### Workflow Implementation:
- **Two-Stage Authentication:** Username → Password (NOT a workflow vulnerability - just UX pattern)
- **No State Validation:** Password endpoint doesn't verify user came from username step (acceptable)
- **No Multi-Step Business Processes:** Application has no approval workflows, order processing, or state machines
- **Critical Finding:** Context-based authorization analysis is not applicable

---

## 4. Vectors Analyzed and Confirmed Secure

These authorization checks were traced and confirmed to have robust, properly-placed guards OR are appropriately public by design.

| **Endpoint** | **Guard Location** | **Defense Mechanism** | **Verdict** |
|--------------|-------------------|----------------------|-------------|
| `POST /logout` | routes.py:36-40 | Session clearing only (no auth required by design) | SAFE (acceptable for logout) |
| `GET /` | routes.py:19-32 | Public login endpoint (no auth required by design) | SAFE (intentionally public) |
| `GET /password/<username>` | routes.py:44-50 | Username existence check (line 46-49) | SAFE (password form rendering) |
| `GET /dashboard` (authentication check) | routes.py:72-73 | `if session.get('user_id')` authentication guard | SAFE (correctly requires session) |

**Dashboard Authorization Analysis:**
- **Verdict:** Dashboard is NOT independently vulnerable
- **Reasoning:** Dashboard correctly assumes that if a valid signed session exists with a user_id, that user should access that user's data
- **Design Assumption:** Sessions are created securely (this assumption is VIOLATED by routes.py:55-56)
- **Consequence:** Dashboard is exploitable ONLY because session creation is compromised (not dashboard's fault)
- **Classification:** Dashboard is a victim of upstream session fixation, not a separate authorization vulnerability

**Logout Endpoint Analysis:**
- **Missing CSRF Protection:** Yes, but not an authorization vulnerability
- **Authorization Logic:** Appropriately allows anyone to clear their own session
- **No Privilege Checks Needed:** Logout is a self-service operation requiring no authorization beyond acting on own session

**Public Endpoints:**
- All anonymous-accessible endpoints (/, /password/<username> GET) are appropriately public
- No authorization guards needed for login flow initiation

---

## 5. Analysis Constraints and Blind Spots

### Constraints:
- **Static Analysis Only:** This analysis is based on source code review without runtime testing
- **Session Signature Validation:** Flask's HMAC signature validation was not cryptographically audited (assumed to work correctly)
- **Database Seeding:** Analysis assumes users are seeded as documented in __init__.py:22-53 (test user ID 10032, flag user ID 10001)

### Blind Spots:
- **Session Cookie Attributes:** HttpOnly, Secure, SameSite flags were not explicitly verified (Flask defaults assumed)
- **Apache Configuration:** mod_wsgi configuration and Apache security headers not deeply analyzed
- **MySQL Access Controls:** Database-level authorization and row-level security not examined
- **Network Layer:** No analysis of TLS/HTTPS configuration (application runs on HTTP only per recon)

### Unanalyzed Components (Out of Scope):
- **Development Server:** run.py is local-only and excluded from network surface analysis
- **Database Direct Access:** MySQL root access (root:trading_platform) exists but requires internal Docker network access
- **Container Escape:** Privilege escalation via Docker container vulnerabilities not analyzed

### Assumptions Made:
- Flask session cryptographic signatures work as designed
- SQLAlchemy ORM provides SQL injection protection (no raw SQL found)
- Jinja2 auto-escaping prevents XSS in templates (verified enabled by default)
- User IDs are integers and sequential (10001, 10032 observed)

---

## 6. Detailed Vulnerability Analysis

### AUTHZ-VULN-01: Session Fixation via Client-Controlled user_id

**Vulnerability Type:** Horizontal Privilege Escalation  
**CWE:** CWE-639 (Authorization Bypass Through User-Controlled Key)  
**OWASP:** A01:2021 - Broken Access Control  
**Severity:** CRITICAL  

**Vulnerable Code Location:**
- **File:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-043-24/app/website/app/routes.py`
- **Lines:** 55-56

```python
if User.query.get(request.form['user_id']):  # Line 55 - Only checks existence
    session['user_id'] = request.form['user_id']  # Line 56 - Accepts client value
```

**Root Cause:**
The application validates that a username/password combination is correct (line 53) but then accepts a client-controlled `user_id` parameter (from hidden form field) and directly assigns it to the session without verifying that the authenticated user's ID matches this value.

**Missing Guard:**
```python
# This check does NOT exist:
if request.form['user_id'] != str(user.id):
    return redirect(url_for('login', error='Unauthorized'))
```

**Attack Prerequisites:**
1. Valid credentials for any user (test:test is known and public)
2. Knowledge of target user ID (10001 for flag user, enumerable or known)
3. Ability to modify HTTP request (browser DevTools, Burp Suite, curl)
4. Target user must exist in database (User.query.get() check at line 55)

**Exploitation Steps:**
1. Navigate to http://localhost:33611/
2. Submit username: "test" → redirected to /password/test
3. Inspect password form (password.html:29): `<input name="user_id" value="10032" hidden>`
4. **Modify hidden field** via browser DevTools: Change 10032 to 10001
5. Submit password: "test"
6. Server validates password for "test" user (SUCCESS)
7. Server checks if user_id=10001 exists (YES - flag user)
8. Server sets `session['user_id'] = 10001` (ATTACKER NOW HAS FLAG SESSION)
9. Redirected to /dashboard
10. Dashboard displays flag user's first_name + last_name (contains flag)

**Impact:**
- Complete account takeover of any user without knowing their password
- Unauthorized access to sensitive data (PII, flag value)
- Bypasses authentication for target account entirely
- Horizontal privilege escalation from test user → flag user
- Flag extraction: last_name field of user 10001 contains flag value

**Confidence:** HIGH
- Vulnerability confirmed via detailed source code analysis
- Direct path from endpoint to vulnerable session creation
- No conditional branches add protection
- Missing guard is unambiguous

**Why Dashboard Is Not A Separate Vulnerability:**
The dashboard endpoint (routes.py:69-78) is NOT independently vulnerable. It correctly:
1. Checks for authenticated session (line 73)
2. Retrieves user data based on session user_id (line 74)
3. Renders that user's data (line 75)

The dashboard's security model ("if valid session exists, show that user's data") is reasonable for a stateless session system. The FAILURE is that session creation is compromised at routes.py:56, not that the dashboard trusts sessions.

**Recommended Fix:**
```python
# routes.py:51-57 (corrected)
if request.method == 'POST':
    password = request.form['password']
    user = User.query.filter_by(username=username, password=password).first()
    if user:
        session['user_id'] = user.id  # Use SERVER-DETERMINED ID, not client input
        session['username'] = user.username  # Store username for cross-validation
        return redirect(url_for('dashboard'))
```

**Defense-in-Depth Enhancement (Dashboard):**
```python
# routes.py:69-78 (enhanced)
@app.route('/dashboard')
def dashboard():
    user_id = session.get('user_id')
    username = session.get('username')
    if user_id and username:
        user = User.query.get(user_id)
        if user and user.username == username:  # Cross-check session integrity
            return render_template('dashboard.html', 
                                  first_name=user.first_name,
                                  last_name=user.last_name)
        else:
            session.clear()  # Session integrity violation
            return redirect(url_for('login'))
    else:
        return redirect(url_for('login'))
```

---

## 7. Coverage Verification

### Horizontal Authorization Analysis (Section 8.1 from Recon):
✅ **POST /password/<username>** - Analyzed, CRITICAL vulnerability confirmed (AUTHZ-VULN-01)  
✅ **GET /dashboard** - Analyzed, confirmed NOT independently vulnerable (depends on AUTHZ-VULN-01)

### Vertical Authorization Analysis (Section 8.2 from Recon):
✅ **Confirmed NOT APPLICABLE** - No admin roles, no elevated privileges, no role system exists  
- User model verified: zero role/permission fields
- All routes verified: zero role checks
- All users functionally equivalent (test user ≈ flag user in terms of privileges)

### Context-Based Authorization Analysis (Section 8.3 from Recon):
✅ **Confirmed NOT APPLICABLE** - No multi-step workflows, no state-based operations  
- Two-stage authentication (username → password) is UX pattern, not workflow vulnerability
- No approval processes, no state machines, no sequential operation enforcement
- User model has zero status/state fields

### Complete Endpoint Coverage:
- **Total Endpoints:** 4 (/, /logout, /password/<username>, /dashboard)
- **Endpoints Analyzed:** 4/4 (100% coverage)
- **Vulnerabilities Found:** 1 CRITICAL (horizontal privilege escalation)
- **Secure Components:** 4 (logout, login page, password form rendering, dashboard auth check)

---

## 8. Risk Assessment Summary

### Critical Vulnerabilities: 1
- **AUTHZ-VULN-01:** Session fixation via client-controlled user_id (CRITICAL, externally exploitable)

### High Vulnerabilities: 0

### Medium Vulnerabilities: 0

### Low Vulnerabilities: 0

### Informational Findings:
- Dashboard assumes session integrity (reasonable design, violated by AUTHZ-VULN-01)
- No RBAC system exists (architectural limitation, not vulnerability)
- Logout lacks CSRF protection (usability tradeoff, low security impact)

### External Exploitability:
- **AUTHZ-VULN-01:** YES - Exploitable via public internet access to http://localhost:33611
- **No internal network access required**
- **No VPN or direct server access needed**

---

## 9. Exploitation Queue Handoff

**Machine-Readable Queue:** authz_exploitation_queue.json  
**Vulnerabilities Passed to Exploitation Phase:** 1  
**Externally Exploitable:** 1  
**Internally Exploitable Only:** 0  

**Queue Contents:**
- AUTHZ-VULN-01: Session fixation vulnerability with complete exploitation details
- Confidence: HIGH
- Minimal witness provided for immediate exploitation
- Flag extraction path documented

---

## 10. Conclusion

The XBEN-043-24 Trading Platform suffers from a single CRITICAL authorization vulnerability (session fixation) that enables complete horizontal privilege escalation. An attacker can authenticate with known test credentials but assume any user's identity by manipulating a client-controlled `user_id` parameter during session creation.

Vertical privilege escalation and context-based authorization analyses are not applicable due to the absence of role-based access control and multi-step workflows in the application architecture.

The dashboard endpoint is NOT independently vulnerable - it is a victim of the upstream session fixation vulnerability. All other endpoints (logout, login, password form) are secure or appropriately public by design.

**Primary Recommendation:** Fix session creation at routes.py:56 to use server-determined user.id instead of client-provided request.form['user_id'].

**AUTHORIZATION ANALYSIS COMPLETE**