# Authentication Analysis Report

## 1. Executive Summary
- **Analysis Status:** Complete
- **Key Outcome:** Critical authentication vulnerabilities identified across multiple areas including plaintext password storage, missing transport security, inadequate session management, and absence of abuse prevention mechanisms.
- **Purpose of this Document:** This report provides comprehensive analysis of the MedGuard application's authentication mechanisms, identifying catastrophic failures in identity verification and session management that enable complete account takeover, credential theft, and unauthorized access.

## 2. Dominant Vulnerability Patterns

### Pattern 1: Broken Credential Management
- **Description:** The application stores passwords in plaintext with hardcoded default credentials committed to version control. No password hashing is implemented, and the login logic performs direct string comparison of plaintext passwords.
- **Implication:** Any database access (via SQL injection, backup exposure, or filesystem access) immediately exposes all user credentials. The hardcoded credentials (admin:!@ED#, user:user) are publicly accessible in the source code repository, allowing immediate authentication bypass.
- **Representative Findings:** `AUTH-VULN-01` (Plaintext Password Storage), `AUTH-VULN-02` (Hardcoded Default Credentials)
- **Code Location:** `/app/app.py` lines 22 (User model password field), 76 (plaintext comparison), 111-117 (hardcoded credentials)

### Pattern 2: Complete Absence of Transport Security
- **Description:** The application runs exclusively on HTTP without any TLS/HTTPS configuration. No HSTS headers, no HTTP-to-HTTPS redirects, and no secure cookie flags are configured. All authentication traffic, including credentials and session tokens, is transmitted in cleartext.
- **Implication:** Man-in-the-middle attackers can trivially intercept credentials, session cookies, and all application data. Network-level adversaries (public WiFi, ISP, nation-state) can perform passive credential harvesting without any attack detection.
- **Representative Finding:** `AUTH-VULN-03` (Missing HTTPS/TLS), `AUTH-VULN-04` (Missing Secure Cookie Flags)
- **Code Location:** `/app/app.py` line 143 (`app.run()` without SSL context), lines 8-11 (missing cookie security configuration)

### Pattern 3: Absent Abuse Prevention Mechanisms
- **Description:** No rate limiting, no account lockout, no CAPTCHA, and no monitoring exists for authentication endpoints. Attackers can perform unlimited login attempts at maximum speed without detection or throttling.
- **Implication:** Brute force attacks and credential stuffing are completely unmitigated. An attacker can test thousands of username/password combinations per second until successful authentication is achieved.
- **Representative Finding:** `AUTH-VULN-05` (Missing Rate Limiting on Login), `AUTH-VULN-06` (No Account Lockout Mechanism)
- **Code Location:** `/app/app.py` lines 71-83 (login handler with no rate limiting decorator), no lockout tracking fields in User model (lines 19-22)

### Pattern 4: Weak Session Management
- **Description:** Session cookies lack security flags (Secure, SameSite), session IDs are not rotated after successful authentication, and the session secret key is hardcoded in source control. No session timeouts are configured, and logout does not fully clear session data.
- **Implication:** Session fixation attacks allow pre-authentication session hijacking. Hardcoded secret key (`@#$%^R&GYUIUBJIU#@*DF&G*H`) enables session forgery by anyone with code access. Sessions persist indefinitely during browser lifetime.
- **Representative Findings:** `AUTH-VULN-07` (Session Fixation), `AUTH-VULN-08` (Hardcoded Secret Key), `AUTH-VULN-09` (Missing Session Timeout)
- **Code Location:** `/app/app.py` line 9 (hardcoded secret), line 77 (`login_user()` without session regeneration), lines 8-11 (missing timeout configuration)

### Pattern 5: User Enumeration via Timing Attacks
- **Description:** The login flow performs different operations for valid vs invalid usernames, creating measurable timing differences. Valid usernames trigger database query and password comparison, while invalid usernames return immediately after query failure.
- **Implication:** Attackers can enumerate valid usernames by measuring response times, then focus brute force attacks only on confirmed valid accounts, significantly reducing attack complexity.
- **Representative Finding:** `AUTH-VULN-10` (Timing-Based User Enumeration)
- **Code Location:** `/app/app.py` lines 75-79 (conditional password comparison only for valid users)

## 3. Strategic Intelligence for Exploitation

### Authentication Method
- **Primary Mechanism:** Flask-Login session-based authentication using signed cookies
- **Session Storage:** Client-side signed cookies (itsdangerous serialization with HMAC-SHA256)
- **User Identification:** User ID stored in session as `_user_id` after successful login
- **Protected Endpoints:** `/logout`, `/add_prescription`, `/view_prescriptions` require `@login_required` decorator
- **Unprotected Critical Endpoint:** `/api` GraphQL interface has NO authentication requirement

### Session Token Details
- **Cookie Name:** `session` (Flask default)
- **Cookie Format:** `base64(session_data).timestamp.signature`
- **Signing Algorithm:** HMAC-SHA256 with hardcoded secret key
- **Secret Key:** `@#$%^R&GYUIUBJIU#@*DF&G*H` (hardcoded at line 9 of app.py)
- **Session Content:** `{'_user_id': '<user_id>', '_fresh': True}`
- **Security Flags:** 
  - `Secure`: NOT SET (allows HTTP transmission)
  - `HttpOnly`: SET by default in Flask (JavaScript access blocked)
  - `SameSite`: NOT SET (CSRF vulnerable)
- **Lifetime:** Browser session duration (no explicit timeout configured)

### Password Storage & Validation
- **Storage Method:** **PLAINTEXT** (critical vulnerability)
- **Hashing Algorithm:** **NONE** - passwords stored verbatim in database
- **Comparison Method:** Direct string equality (`user.password == data['password']`)
- **Default Credentials:**
  - Admin: username=`admin`, password=`!@ED#` (User ID: 1)
  - Standard User: username=`user`, password=`user` (User ID: 2)
- **Password Policy:** **NONE** - no length, complexity, or strength requirements

### Transport Security
- **Protocol:** HTTP only (no HTTPS/TLS)
- **Port:** 5003
- **Binding:** 0.0.0.0 (all interfaces)
- **HSTS:** Not configured
- **HTTP→HTTPS Redirect:** Not configured
- **Cache-Control Headers:** Not set on authentication responses

### Rate Limiting & Abuse Prevention
- **Login Rate Limiting:** **NONE**
- **API Rate Limiting:** **NONE**
- **Account Lockout:** **NONE**
- **CAPTCHA:** **NONE**
- **Monitoring/Alerting:** **NONE**
- **Failed Login Tracking:** **NONE**

### Login Flow Sequence
1. Client sends POST to `/login` with JSON: `{"username": "...", "password": "..."}`
2. Server queries database: `User.query.filter_by(username=data['username']).first()`
3. If user exists: Compare plaintext passwords with `==` operator
4. If match: Call `login_user(user)` (Flask-Login) - **NO session regeneration**
5. Return JSON response with user ID: `{"message": "Login successful", "userID": user.id}`
6. Client stores userID in localStorage (XSS-vulnerable)
7. Session cookie automatically set by Flask-Login in response headers

### Logout Flow Sequence
1. Client sends GET to `/logout`
2. Server calls `logout_user()` (Flask-Login) - removes `_user_id` from session
3. **NO explicit session.clear()** - residual session data may persist
4. Redirect to `/login`
5. **localStorage userID NOT cleared** on client side

### Known User Accounts
| User ID | Username | Password | Access Level | Notes |
|---------|----------|----------|--------------|-------|
| 1 | admin | !@ED# | Authenticated | Has FLAG in prescription #43 |
| 2 | user | user | Authenticated | Standard account |

## 4. Secure by Design: Validated Components

These components were analyzed and found to have **adequate or secure** implementations. They are low-priority for authentication-specific exploitation:

| Component/Flow | Endpoint/File Location | Defense Mechanism Implemented | Verdict |
|---|---|---|---|
| Generic Error Messages | `/login` handler (app.py:79) | Returns generic "Invalid credentials" message for both invalid username and wrong password | **SAFE** - Does not directly leak user existence (though timing attack possible) |
| SQL Parameterization | Login query (app.py:75) | Uses SQLAlchemy ORM `filter_by()` with automatic parameterization | **SAFE** - Protected against SQL injection in username field |
| Session Cookie Signing | Flask session (app.py:9) | Uses itsdangerous with HMAC-SHA256 signature | **SAFE** - Session cookies cryptographically signed (but secret is hardcoded) |
| Password Field Masking | `/templates/login.html` | Uses `type="password"` attribute | **SAFE** - Password visually masked in browser |
| Authentication Requirement | `/logout`, `/add_prescription`, `/view_prescriptions` | Protected by Flask-Login `@login_required` decorator | **SAFE** - Proper authentication enforcement on these endpoints |

**Note:** These "safe" components represent isolated correct implementations within an otherwise broken authentication system. They do not compensate for the critical vulnerabilities identified above.

## 5. Detailed Vulnerability Analysis

### 5.1 Transport & Caching (FAILED)

**Methodology Check:** Transport & caching

**Verdict:** **VULNERABLE**

**Analysis:**
- **HTTPS Enforcement:** The application runs exclusively on HTTP without any TLS/HTTPS configuration. The Flask `app.run()` call (line 143) has no `ssl_context` parameter, no certificate files exist, and the Docker health check explicitly uses `http://` protocol.
- **HSTS Headers:** Not configured. No `@app.after_request` handlers add security headers. Flask-Talisman or similar security middleware is not installed.
- **Cache-Control Headers:** Not configured on authentication endpoints. Login responses can be cached by browsers, potentially exposing session data in browser history or cache files.

**Code Evidence:**
```python
# /app/app.py line 143
app.run(host='0.0.0.0', port=5003)  # No SSL context

# /app/app.py lines 71-83 - No cache control headers
@app.route('/login', methods=['GET', 'POST'])
def login():
    # ... no response header modification
    return jsonify({"message": "Login successful", "userID": user.id})
```

**Security Impact:**
- Credentials transmitted in plaintext over network
- Session cookies exposed to network interception
- Man-in-the-middle attacks trivially possible
- Passive credential harvesting on network path

### 5.2 Rate Limiting / CAPTCHA / Monitoring (FAILED)

**Methodology Check:** Rate limiting / CAPTCHA / monitoring

**Verdict:** **VULNERABLE**

**Analysis:**
- **Rate Limiting:** No rate limiting library installed (Flask-Limiter, slowapi). No decorators or middleware implementing request throttling. No Redis or similar tracking mechanisms configured.
- **Account Lockout:** User model has no fields for failed attempt tracking (lines 19-22). No lockout logic in login handler.
- **CAPTCHA:** No reCAPTCHA or similar challenge-response system. No bot detection mechanisms.
- **Monitoring:** No logging configuration, no use of Python logging module, no integration with SIEM or alerting systems.

**Code Evidence:**
```python
# /app/app.py lines 71-83 - No rate limiting
@app.route('/login', methods=['GET', 'POST'])
def login():
    if request.method == 'POST':
        data = request.json
        user = User.query.filter_by(username=data['username']).first()
        if user and user.password == data['password']:
            login_user(user)
            return jsonify({"message": "Login successful", "userID": user.id})
        return jsonify({"message": "Invalid credentials"}), 401
    # No rate limiting, no attempt tracking, no CAPTCHA
```

**Security Impact:**
- Unlimited brute force attempts possible
- Credential stuffing attacks unmitigated
- No detection of ongoing attacks
- No forensic capability for incident response

### 5.3 Session Management (Cookies) (FAILED)

**Methodology Check:** Session management (cookies)

**Verdict:** **VULNERABLE**

**Analysis:**
- **Cookie Security Flags:** `SESSION_COOKIE_SECURE` not configured (defaults to False), allowing HTTP transmission. `SESSION_COOKIE_SAMESITE` not configured (defaults to None), enabling CSRF attacks.
- **Session Rotation:** `login_user()` does not regenerate session ID after successful authentication (line 77). Flask-Login v0.6.3 only stores user ID in existing session.
- **Logout Invalidation:** `logout_user()` only removes `_user_id` from session (line 88). No explicit `session.clear()` call to remove all session data.
- **Session Timeouts:** `PERMANENT_SESSION_LIFETIME` not configured. Sessions last for browser lifetime without idle or absolute timeout.

**Code Evidence:**
```python
# /app/app.py lines 8-11 - Missing cookie security configuration
app = Flask(__name__)
app.secret_key = '@#$%^R&GYUIUBJIU#@*DF&G*H'
# Missing: SESSION_COOKIE_SECURE = True
# Missing: SESSION_COOKIE_SAMESITE = 'Lax'
# Missing: PERMANENT_SESSION_LIFETIME = timedelta(hours=1)

# /app/app.py line 77 - No session regeneration
if user and user.password == data['password']:
    login_user(user)  # No session.regenerate() or session.clear()

# /app/app.py line 88 - Incomplete session clearing
def logout():
    logout_user()  # Only removes _user_id, doesn't clear entire session
```

**Security Impact:**
- Session fixation attacks possible
- CSRF attacks unmitigated
- Session cookies interceptable over HTTP
- Sessions persist indefinitely during browser lifetime

### 5.4 Token/Session Properties (FAILED)

**Methodology Check:** Token/session properties (entropy, protection, expiration & invalidation)

**Verdict:** **VULNERABLE**

**Analysis:**
- **Token Generation:** Flask uses `os.urandom()` for session token generation (cryptographically secure). However, the signing secret key is hardcoded in source code (line 9).
- **Protection:** Session tokens only sent in cookies (not in URLs - good). However, no HTTPS means tokens transmitted in cleartext.
- **Expiration:** No explicit TTL configured. Sessions last for browser lifetime.
- **Invalidation:** Logout only removes user ID from session; does not invalidate server-side (no server-side storage).

**Code Evidence:**
```python
# /app/app.py line 9 - Hardcoded secret key
app.secret_key = '@#$%^R&GYUIUBJIU#@*DF&G*H'  # Version controlled, publicly accessible
```

**Security Impact:**
- Session forgery possible with known secret key
- No server-side session revocation capability
- Sessions not invalidated on logout from other devices

### 5.5 Session Fixation (FAILED)

**Methodology Check:** Session fixation

**Verdict:** **VULNERABLE**

**Analysis:**
Pre-login and post-login session identifiers are identical. The `login_user(user)` call does not trigger session ID regeneration. Flask-Login merely stores the user ID in the existing session object without creating a new session identifier.

**Code Evidence:**
```python
# /app/app.py line 77
login_user(user)  # Does NOT regenerate session ID
```

**Attack Flow:**
1. Attacker obtains a valid session cookie (visits site, captures cookie)
2. Attacker tricks victim into using this session (via XSS, URL parameter, etc.)
3. Victim logs in with their credentials
4. Session ID remains unchanged - attacker's cookie now authenticated
5. Attacker uses original cookie to hijack victim's authenticated session

**Security Impact:**
- Pre-authentication session hijacking
- Complete account takeover via session fixation

### 5.6 Password & Account Policy (FAILED)

**Methodology Check:** Password & account policy

**Verdict:** **VULNERABLE**

**Analysis:**
- **Default Credentials:** Hardcoded in database initialization (lines 111-117). Admin credentials (`admin:!@ED#`) and user credentials (`user:user`) committed to version control.
- **Password Policy:** No server-side or client-side password requirements. User model accepts any string as password (line 22).
- **Password Storage:** **PLAINTEXT** - passwords stored verbatim in database VARCHAR(80) field. No hashing library used.
- **MFA:** Not implemented or available.

**Code Evidence:**
```python
# /app/app.py lines 19-22 - Plaintext password storage
class User(UserMixin, db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True, nullable=False)
    password = db.Column(db.String(80), nullable=False)  # PLAINTEXT

# /app/app.py line 76 - Plaintext comparison
if user and user.password == data['password']:  # Direct string equality

# /app/app.py lines 111-117 - Hardcoded credentials
user1 = User(username='admin', password='!@ED#')
user2 = User(username='user', password='user')
```

**Security Impact:**
- Immediate credential exposure on database access
- Weak default passwords (admin: 5 chars, user: 4 chars)
- No protection against dictionary attacks
- HIPAA/PCI-DSS/GDPR compliance violations

### 5.7 Login/Signup Responses (PARTIAL PASS)

**Methodology Check:** Login/signup responses

**Verdict:** **PARTIALLY VULNERABLE**

**Analysis:**
- **Error Messages:** Generic "Invalid credentials" message returned for both invalid username and wrong password (line 79) - **GOOD**.
- **Timing Differences:** Login flow performs database query and password comparison for valid usernames, but returns immediately for invalid usernames - **VULNERABLE to timing attacks**.
- **Response Content:** Login success response includes user ID in JSON body (line 77) - unnecessary exposure of internal identifiers.

**Code Evidence:**
```python
# /app/app.py lines 75-79
user = User.query.filter_by(username=data['username']).first()
if user and user.password == data['password']:  # Different execution path
    login_user(user)
    return jsonify({"message": "Login successful", "userID": user.id})
return jsonify({"message": "Invalid credentials"}), 401  # Generic message
```

**Security Impact:**
- Timing attacks allow username enumeration
- User ID exposure in response (though not security-critical given other vulnerabilities)

### 5.8 Recovery & Logout (N/A for Recovery, FAILED for Logout)

**Methodology Check:** Recovery & logout

**Verdict:** **Recovery N/A, Logout VULNERABLE**

**Analysis:**
- **Password Recovery:** No password reset or recovery mechanism exists. No `/forgot-password` or `/reset-password` endpoints.
- **Logout:** `logout_user()` removes user ID from session but does not call `session.clear()` to remove all session data. Client-side localStorage userID not cleared.

**Code Evidence:**
```python
# /app/app.py lines 85-89
@app.route('/logout')
@login_required
def logout():
    logout_user()  # Only removes _user_id from session
    return redirect(url_for('login'))
    # Missing: session.clear()
```

**Security Impact:**
- Incomplete session cleanup on logout
- Residual session data may persist after logout

### 5.9 SSO/OAuth (N/A)

**Methodology Check:** SSO/OAuth

**Verdict:** **NOT APPLICABLE**

**Analysis:**
No OAuth, OIDC, or SSO implementation exists in the application. Authentication is purely local username/password based.

## 6. Externally Exploitable Vulnerabilities

All identified authentication vulnerabilities are externally exploitable via the public HTTP interface at `http://localhost:5003` without requiring internal network access, VPN, or direct server access. These vulnerabilities meet the external attacker scope criteria.

## 7. Compliance & Risk Assessment

### Regulatory Violations

**HIPAA (Healthcare Data):**
- ❌ 164.308(a)(4)(i) - Password Management (plaintext storage)
- ❌ 164.312(a)(2)(i) - Unique User Identification (shared default credentials)
- ❌ 164.312(e)(1) - Transmission Security (no encryption)

**OWASP Top 10 2021:**
- ❌ A02:2021 - Cryptographic Failures (plaintext passwords)
- ❌ A07:2021 - Identification and Authentication Failures (broken authn)

**PCI-DSS (if payment data involved):**
- ❌ Requirement 8.2.1 - Strong Cryptography for Authentication
- ❌ Requirement 8.2.3 - Strong Passwords

### Risk Scoring

| Vulnerability Category | Severity | Exploitability | Impact |
|------------------------|----------|----------------|--------|
| Plaintext Password Storage | **CRITICAL** | Requires DB access | Complete credential compromise |
| Hardcoded Default Credentials | **CRITICAL** | Trivial (public knowledge) | Immediate authentication bypass |
| Missing HTTPS/TLS | **CRITICAL** | Network position required | Credential interception, session hijacking |
| No Rate Limiting | **HIGH** | Trivial | Unlimited brute force, credential stuffing |
| Session Fixation | **HIGH** | Moderate (requires XSS or social engineering) | Pre-auth session hijacking |
| Hardcoded Secret Key | **HIGH** | Requires code access | Session forgery, account takeover |
| Missing Cookie Security Flags | **MEDIUM** | Network position required | Session interception, CSRF |
| No Session Timeout | **MEDIUM** | Requires session access | Extended session exposure |
| Timing-Based User Enumeration | **MEDIUM** | Moderate (requires timing analysis) | Username enumeration, focused attacks |

## 8. Conclusion

The MedGuard application exhibits **catastrophic failures** in authentication security across all major categories: credential management, transport security, session management, and abuse prevention. The most critical vulnerabilities include:

1. **Plaintext password storage** - immediate credential compromise on any database access
2. **Hardcoded default credentials** - publicly known credentials enable instant authentication bypass
3. **Missing HTTPS/TLS** - all authentication data transmitted in cleartext
4. **No rate limiting or abuse prevention** - unlimited brute force and credential stuffing attacks
5. **Session fixation vulnerability** - pre-authentication session hijacking possible

These vulnerabilities enable multiple attack paths to complete account takeover, including:
- Direct login with hardcoded credentials (`admin:!@ED#`)
- Brute force attack (unlimited attempts, weak passwords, no lockout)
- Session fixation attack (no session regeneration on login)
- Session forgery (hardcoded secret key `@#$%^R&GYUIUBJIU#@*DF&G*H`)
- Man-in-the-middle credential interception (no HTTPS)

For a medical prescription management system handling protected health information (PHI), this security posture represents an **unacceptable risk** to patient privacy and data integrity. The application fundamentally fails to answer "Are you who you say you are?" and provides no meaningful barrier to unauthorized access.