CVE-2019-12240
📋 TL;DR
CVE-2019-12240 is an insecure deserialization vulnerability in the Virim WordPress plugin that allows attackers to execute arbitrary code on affected websites. This affects WordPress sites running Virim plugin version 0.4, potentially leading to complete system compromise. Attackers can exploit this without authentication by sending specially crafted requests to the vulnerable graph.php endpoint.
💻 Affected Systems
- WordPress Virim Plugin
📦 What is this software?
Virim by Virim Project
⚠️ Risk & Real-World Impact
Worst Case
Complete server takeover with remote code execution, data theft, website defacement, and installation of persistent backdoors.
Likely Case
Website compromise leading to malware injection, credential theft, and unauthorized administrative access to the WordPress installation.
If Mitigated
Limited impact with proper input validation and deserialization controls in place, potentially reduced to denial of service.
🎯 Exploit Status
Exploitation is straightforward with publicly available proof-of-concept code. Attackers can send malicious serialized data via s_values, t_values, or c_values parameters.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 0.5 or later
Vendor Advisory: https://wordpress.org/plugins/virim/
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find Virim plugin and click 'Update Now'. 4. Alternatively, delete the plugin and install the latest version from WordPress repository.
🔧 Temporary Workarounds
Disable Virim Plugin
allTemporarily deactivate the vulnerable plugin until patching is possible.
wp plugin deactivate virim
Block Access to graph.php
linuxUse web server configuration to block access to the vulnerable file.
# Apache: <Location /wp-content/plugins/virim/graph.php>\n Order deny,allow\n Deny from all\n</Location>
# Nginx: location ~ /wp-content/plugins/virim/graph\.php { deny all; }
🧯 If You Can't Patch
- Remove the Virim plugin completely from the WordPress installation
- Implement web application firewall rules to block requests containing serialized data patterns
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin panel → Plugins → Installed Plugins for Virim version 0.4. Alternatively, check file system: /wp-content/plugins/virim/readme.txt for version information.Check Version:
wp plugin list --name=virim --field=versionVerify Fix Applied:
Verify Virim plugin version is 0.5 or higher in WordPress admin panel or check that graph.php file no longer contains insecure deserialization code.📡 Detection & Monitoring
Log Indicators:
- HTTP requests to /wp-content/plugins/virim/graph.php with serialized data in parameters
- Unusual PHP process execution from web server context
- WordPress plugin activation/deactivation logs for Virim
Network Indicators:
- POST requests to graph.php endpoint with s_values, t_values, or c_values parameters containing serialized data
- Outbound connections from web server to suspicious IPs following exploitation
SIEM Query:
source="web_access_logs" AND uri="/wp-content/plugins/virim/graph.php" AND (param="s_values" OR param="t_values" OR param="c_values")