CVE-2024-33424
📋 TL;DR
This cross-site scripting (XSS) vulnerability in CMSimple v5.15 allows attackers to inject malicious scripts into the Settings menu's Downloads parameter under Language section. When exploited, it enables execution of arbitrary web scripts or HTML in the context of the victim's browser. Administrators and users accessing the CMSimple admin interface are primarily affected.
💻 Affected Systems
- CMSimple
📦 What is this software?
Cmsimple by Cmsimple
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator session cookies, perform actions as administrators, deface websites, or redirect users to malicious sites, potentially leading to complete system compromise.
Likely Case
Attackers with access to the admin interface could inject persistent XSS payloads that affect all users visiting the vulnerable page, leading to session hijacking or credential theft.
If Mitigated
With proper input validation and output encoding, the payload would be rendered harmless as text rather than executable code.
🎯 Exploit Status
Exploit requires access to admin interface or social engineering to trick admin into executing payload. Public proof-of-concept available on GitHub.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Unknown
Restart Required: No
Instructions:
No official patch available. Consider upgrading to newer CMSimple version if available, or implement workarounds.
🔧 Temporary Workarounds
Input Validation and Sanitization
allImplement server-side validation and sanitization of the Downloads parameter in Language settings
Modify CMSimple source code to validate and sanitize user input in the affected parameter
Content Security Policy (CSP)
allImplement strict CSP headers to prevent execution of inline scripts
Add Content-Security-Policy header to web server configuration
🧯 If You Can't Patch
- Restrict access to CMSimple admin interface to trusted IP addresses only
- Implement web application firewall (WAF) rules to block XSS payload patterns
🔍 How to Verify
Check if Vulnerable:
Check if CMSimple version is 5.15 and test XSS payload injection in Downloads parameter under Language section in SettingsCheck Version:
Check CMSimple version in admin dashboard or configuration filesVerify Fix Applied:
Test XSS payload injection after implementing workarounds to ensure scripts no longer execute📡 Detection & Monitoring
Log Indicators:
- Unusual parameter values in Language settings requests
- Script tags or JavaScript in Downloads parameter
Network Indicators:
- HTTP requests containing script tags or encoded payloads in Language section parameters
SIEM Query:
web_requests WHERE url_path CONTAINS 'language' AND (parameter_value CONTAINS '<script' OR parameter_value CONTAINS 'javascript:')