CVE-2020-18912
📋 TL;DR
CVE-2020-18912 is a critical remote code execution vulnerability in Earcms Ear App v.20181124 that allows attackers to execute arbitrary code via the uload/index-uplog.php endpoint. This affects all systems running the vulnerable version of Earcms Ear App, potentially compromising web servers and their underlying infrastructure.
💻 Affected Systems
- Earcms Ear App
📦 What is this software?
Ear by Earcms
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary commands, install malware, steal data, pivot to internal networks, and maintain persistent access.
Likely Case
Web server compromise leading to data theft, defacement, or use as a foothold for further attacks within the network.
If Mitigated
Attack blocked at perimeter with no internal access; minimal impact if proper segmentation and monitoring are in place.
🎯 Exploit Status
Exploit details are publicly available in blog posts; simple HTTP requests can trigger the vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: No official vendor advisory found
Restart Required: No
Instructions:
1. Check for updated version from vendor. 2. If no patch, remove or disable the vulnerable component. 3. Consider migrating to alternative software.
🔧 Temporary Workarounds
Block access to vulnerable endpoint
allRestrict access to uload/index-uplog.php via web server configuration or firewall rules.
# Apache: RewriteRule ^uload/index-uplog\.php$ - [F,L]
# Nginx: location ~ /uload/index-uplog\.php { deny all; }
Disable file upload functionality
linuxRemove or rename the uload directory to prevent exploitation.
mv /path/to/uload /path/to/uload.disabled
🧯 If You Can't Patch
- Implement strict network segmentation to isolate the vulnerable system
- Deploy web application firewall (WAF) with rules to block exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check if uload/index-uplog.php exists and is accessible via HTTP requests; test with controlled payload if safe.Check Version:
Check application files or documentation for version information; grep for '20181124' in source files.Verify Fix Applied:
Verify uload/index-uplog.php returns 403/404 or is inaccessible; test exploitation attempts are blocked.📡 Detection & Monitoring
Log Indicators:
- HTTP requests to uload/index-uplog.php with suspicious parameters
- Unusual file uploads or command execution in web logs
Network Indicators:
- POST requests to uload/index-uplog.php with shell commands or encoded payloads
SIEM Query:
source="web_logs" AND uri="/uload/index-uplog.php" AND (method="POST" OR params CONTAINS "cmd" OR params CONTAINS "system")