CVE-2025-59116
📋 TL;DR
Windu CMS version 4.1 is vulnerable to user enumeration during login, allowing attackers to determine valid usernames by analyzing response differences. This enables targeted brute force attacks against valid accounts. Only organizations using Windu CMS version 4.1 (before build 2250) are affected.
💻 Affected Systems
- Windu CMS
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers enumerate all valid usernames and successfully brute-force passwords, gaining unauthorized access to multiple user accounts and potentially compromising the entire CMS.
Likely Case
Attackers identify valid administrative or high-privilege accounts and conduct focused password attacks, potentially gaining administrative access to the CMS.
If Mitigated
Attackers can still enumerate usernames but cannot successfully authenticate due to strong passwords, account lockouts, or other authentication controls.
🎯 Exploit Status
Exploitation requires only web access to login page and basic scripting to analyze response differences.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 4.1 build 2250 or later
Vendor Advisory: https://windu.org
Restart Required: No
Instructions:
1. Backup current installation. 2. Download Windu CMS version 4.1 build 2250 or later from windu.org. 3. Replace vulnerable files with patched version. 4. Verify login responses are identical for valid and invalid usernames.
🔧 Temporary Workarounds
Implement Web Application Firewall (WAF)
allConfigure WAF rules to detect and block rapid login attempts and user enumeration patterns.
Rate Limit Login Attempts
allImplement server-side rate limiting on login endpoints to prevent brute force attacks.
🧯 If You Can't Patch
- Implement CAPTCHA or multi-factor authentication on login page
- Monitor logs for unusual login patterns and block suspicious IPs
🔍 How to Verify
Check if Vulnerable:
Test login with valid and invalid usernames; if response messages or timing differ significantly, system is vulnerable.Check Version:
Check Windu CMS admin panel or version file; look for '4.1' and build number lower than 2250.Verify Fix Applied:
After patching, test login with valid and invalid usernames; responses should be identical in timing and content.📡 Detection & Monitoring
Log Indicators:
- Multiple failed login attempts for same username
- Unusual pattern of login attempts with varying usernames
- Login attempts from suspicious IP addresses
Network Indicators:
- High volume of POST requests to login endpoint
- Pattern of login attempts with incremental usernames
SIEM Query:
source="web_logs" AND (url_path="/login" OR url_path="/admin/login") AND (status=401 OR status=200) | stats count by src_ip, username