CVE-2020-21237
📋 TL;DR
This vulnerability in LJCMS v1.11 allows attackers to perform brute force attacks against the user login box, potentially hijacking user accounts. Any system running the vulnerable version is affected, particularly those exposed to the internet without rate limiting or account lockout protections.
💻 Affected Systems
- LJCMS
📦 What is this software?
Ljcms by 8cms
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain administrative access to the CMS, allowing complete system compromise, data theft, defacement, and further network penetration.
Likely Case
Attackers compromise user accounts, potentially gaining access to sensitive content management functions and user data.
If Mitigated
Failed login attempts are logged and monitored, with minimal impact due to account lockout or rate limiting controls.
🎯 Exploit Status
Brute force attacks require no authentication and can be automated with readily available tools.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Unknown
Restart Required: No
Instructions:
No official patch available. Consider upgrading to a newer version if available or implementing workarounds.
🔧 Temporary Workarounds
Implement Account Lockout Policy
allConfigure the system to lock accounts after a specified number of failed login attempts.
Enable Rate Limiting
allImplement rate limiting on login attempts to prevent rapid brute force attacks.
Add CAPTCHA to Login
allImplement CAPTCHA verification on the login page to prevent automated attacks.
🧯 If You Can't Patch
- Implement network-level controls like WAF rules to block excessive login attempts
- Monitor authentication logs for brute force patterns and alert on suspicious activity
🔍 How to Verify
Check if Vulnerable:
Check if running LJCMS version 1.11. Review login functionality for lack of account lockout or rate limiting.Check Version:
Check CMS configuration files or admin panel for version information.Verify Fix Applied:
Test login attempts with multiple failed passwords to verify account lockout or rate limiting is functioning.📡 Detection & Monitoring
Log Indicators:
- Multiple failed login attempts from same IP address
- Rapid succession of authentication failures for same username
Network Indicators:
- High volume of POST requests to login endpoint
- Pattern of failed authentication requests
SIEM Query:
source="auth.log" | stats count by src_ip, username | where count > 10