CVE-2024-42749
📋 TL;DR
This CVE describes a Cross-Site Scripting (XSS) vulnerability in Alto CMS v1.1.13 that allows a local attacker to inject and execute malicious scripts. The vulnerability affects users of Alto CMS version 1.1.13 who have local access to the system. Successful exploitation could lead to session hijacking, data theft, or unauthorized actions on behalf of users.
💻 Affected Systems
- Alto CMS
📦 What is this software?
Alto Cms by Altocms
⚠️ Risk & Real-World Impact
Worst Case
Attacker gains administrative privileges, steals sensitive data, defaces website, or installs backdoors through script execution in admin context.
Likely Case
Attacker steals session cookies or credentials, performs unauthorized actions as logged-in users, or injects malicious content visible to other users.
If Mitigated
Limited impact with proper input validation, output encoding, and Content Security Policy (CSP) headers in place.
🎯 Exploit Status
XSS vulnerabilities are commonly weaponized; local access requirement reduces widespread exploitation risk but increases insider threat potential.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check GitHub repository for latest version
Vendor Advisory: https://github.com/altocms/altocms
Restart Required: No
Instructions:
1. Backup current installation and database
2. Download latest version from GitHub repository
3. Replace vulnerable files with patched versions
4. Clear cache and verify functionality
🔧 Temporary Workarounds
Implement Content Security Policy
allAdd CSP headers to restrict script execution sources
Add to web server config or .htaccess: Header set Content-Security-Policy "default-src 'self'; script-src 'self'"
For Nginx: add_header Content-Security-Policy "default-src 'self'; script-src 'self';";
Input Validation Filter
allAdd server-side input validation for user-supplied data
Implement PHP filter: $clean_input = filter_var($input, FILTER_SANITIZE_STRING);
Use htmlspecialchars() for output: echo htmlspecialchars($data, ENT_QUOTES, 'UTF-8');
🧯 If You Can't Patch
- Restrict local access to CMS admin interface using network segmentation
- Implement web application firewall (WAF) rules to block XSS payload patterns
🔍 How to Verify
Check if Vulnerable:
Check CMS version in admin panel or config files; if version is 1.1.13, system is vulnerable.Check Version:
Check config file or admin dashboard for version informationVerify Fix Applied:
Test XSS payloads in input fields; successful payload execution indicates vulnerability still exists.📡 Detection & Monitoring
Log Indicators:
- Unusual script tags or JavaScript in input fields
- Multiple failed login attempts followed by script injection attempts
- Admin panel access from unusual IP addresses
Network Indicators:
- HTTP requests containing script tags or JavaScript in parameters
- Unusual outbound connections after admin panel access
SIEM Query:
source="web_logs" AND ("<script>" OR "javascript:" OR "onerror=" OR "onload=") AND uri_path="/admin/*"