CVE-2020-18406
📋 TL;DR
CVE-2020-18406 is a vulnerability in cmseasy v7.0.0 that transmits user credentials in plain text without encryption. This allows attackers to intercept login credentials during transmission. Any organization using cmseasy v7.0.0 is affected.
💻 Affected Systems
- cmseasy
📦 What is this software?
Cmseasy by Cmseasy
⚠️ Risk & Real-World Impact
Worst Case
Attackers intercept administrative credentials, gain full control of the CMS, deface websites, steal sensitive data, and potentially pivot to internal networks.
Likely Case
Attackers capture user credentials through network sniffing, leading to unauthorized access, data theft, and potential privilege escalation.
If Mitigated
With proper network segmentation and monitoring, impact is limited to credential exposure without lateral movement.
🎯 Exploit Status
Exploitation requires network access to intercept traffic; no authentication needed for interception.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v7.0.1 or later
Vendor Advisory: https://github.com/source-hunter/cmseasy/issues/1
Restart Required: No
Instructions:
1. Backup current installation. 2. Download latest version from official repository. 3. Replace affected files with patched version. 4. Verify form data is now encrypted via HTTPS.
🔧 Temporary Workarounds
Force HTTPS/TLS Encryption
allConfigure web server to enforce HTTPS for all form submissions
# Apache: Redirect HTTP to HTTPS in .htaccess
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
# Nginx: Redirect HTTP to HTTPS in server block
server {
listen 80;
server_name yourdomain.com;
return 301 https://$server_name$request_uri;
}
🧯 If You Can't Patch
- Implement network-level encryption using VPN or TLS termination proxies for all cmseasy traffic
- Deploy network monitoring and intrusion detection to alert on plain text credential transmission
🔍 How to Verify
Check if Vulnerable:
Use browser developer tools or network analyzer to check if login form submissions are sent via HTTP (not HTTPS) with visible credentialsCheck Version:
Check cmseasy version in admin panel or read version.txt file in installation directoryVerify Fix Applied:
Confirm all form submissions use HTTPS and credentials are encrypted in network traffic📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to login endpoints without HTTPS
- Failed login attempts from unexpected IP addresses
Network Indicators:
- Plain text transmission of credentials in network packets
- HTTP traffic to login forms instead of HTTPS
SIEM Query:
source="web_logs" AND (uri="/login" OR uri="/admin") AND protocol="HTTP" AND method="POST"