Session Fixation (CWE-384) - Security Vulnerability

Session Fixation

Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions.

In a session fixation attack, the attacker sets a user's session ID to a known value before the user authenticates. After authentication, the attacker can use the known session ID to hijack the authenticated session.

Prevalencia

Media

3 lenguajes cubiertos

Impacto

Alto

3 reglas de severidad alta

Prevención

Documentada

3 ejemplos de corrección

2 Prevención

Cómo corregir esta vulnerabilidad

Estrategias de prevención para Session Fixation basadas en 3 reglas de detección de Shoulder.

🟨 JavaScript Ver todo JavaScript detalles →

Express Insecure Session Configuration HIGH

Configure sessions with environment-based secrets and secure cookie flags

+9 -3 javascript

  app.use(session({
-   secret: 'keyboard cat',
-   resave: true,
-   saveUninitialized: true
+   secret: process.env.SESSION_SECRET,
+   cookie: {
+     secure: process.env.NODE_ENV === 'production',
+     httpOnly: true,
+     sameSite: 'strict',
+     maxAge: 1000 * 60 * 60 * 24
+   },
+   resave: false,
+   saveUninitialized: false
  }));

🐹 Go Ver todo Go detalles →

Insecure Session Management HIGH

Use crypto/rand for session IDs with Secure, HttpOnly, and SameSite cookie flags

+10 -4 go

  func createSession(w http.ResponseWriter, r *http.Request) {
-     sessionID := fmt.Sprintf("%d", time.Now().Unix())
-     http.SetCookie(w, &http.Cookie{
-         Name:  "session_id",
-         Value: sessionID,
+     b := make([]byte, 32)
+     rand.Read(b)
+     sessionID := base64.URLEncoding.EncodeToString(b)
+     http.SetCookie(w, &http.Cookie{
+         Name:     "session_id",
+         Value:    sessionID,
+         HttpOnly: true,
+         Secure:   true,
+         SameSite: http.SameSiteStrictMode,
+         MaxAge:   3600,
      })
  }

🐍 Python Ver todo Python detalles →

Session Fixation Vulnerability HIGH

Regenerate the session ID immediately after successful authentication

+10 -4 python

  from flask import session, request
  from flask_login import login_user
  
- @app.route('/login', methods=['POST'])
- def login():
-     user = User.query.filter_by(username=request.form['username']).first()
-     if user and check_password(user.password, request.form['password']):
+ def regenerate_session():
+     data = dict(session)
+     session.clear()
+     session.update(data)
+ 
+ @app.route('/login', methods=['POST'])
+ def login():
+     user = User.query.filter_by(username=request.form['username']).first()
+     if user and check_password(user.password, request.form['password']):
+         regenerate_session()
          login_user(user)
          return redirect('/dashboard')

Prácticas clave

Use predictable values or cookies lack Secure/HttpOnly flags
Use a session ID that the attacker already knows

3 Detección

Encuentra vulnerabilidades en tu código

Usa Shoulder para escanear tu código en busca de patrones Session Fixation. 3 reglas.

terminal

# Scan with Shoulder CLI
npx @shoulderdev/cli trust --cwe=384

# Or scan entire project
npx @shoulderdev/cli trust .

Reglas de Detección (3)

🟨 Javascript 1 rules

Express Insecure Session Configuration HIGH

Detects insecure session configuration including weak secrets, insecure cookies, and missing security flags.

🔷 Typescript 1 rules

Express Insecure Session Configuration HIGH

Detects insecure session configuration including weak secrets, insecure cookies, and missing security flags.

🐹 Go 1 rules

Insecure Session Management HIGH

Session IDs use predictable values or cookies lack Secure/HttpOnly flags.

🐍 Python 1 rules

Session Fixation Vulnerability HIGH

Detects missing session regeneration after authentication, which enables session fixation attacks. Session fixation is a serious authentication vulnerability where an attacker forces a victim to use a session ID that the attacker already knows. The attack works like this: 1. Attacker obtains a valid session ID (e.g., by visiting the login page) 2. Attacker tricks victim into authenticating with that session ID (via URL, cookie injection, etc.) 3. Victim logs in, and the pre-known session ID be

4 Señales de Alerta

Qué buscar en las revisiones de código

Estos patrones indican vulnerabilidades potenciales de Session Fixation. Búscalos durante las revisiones de código y auditorías de seguridad.

🟠

Session configuration has security vulnerabilities express-insecure-session

🟠

insecure session configuration including weak secrets, insecure cookies, and missing security flags express-insecure-session

🟠

Session management has security weaknesses go-insecure-session-management

🟠

missing session regeneration after authentication, which enables session fixation attacks python-session-fixation

🔍

Escanea tu base de código para Session Fixation

Shoulder CLI encuentra patrones vulnerables en toda tu base de código.

npx shoulder trust Ver todas las reglas