CVE-2021-4374
📋 TL;DR
This vulnerability in the WordPress Automatic Plugin allows unauthenticated attackers to modify any WordPress site setting without authorization. It affects WordPress sites using the Automatic Plugin version 3.53.2 or earlier. Attackers can change critical configurations to compromise the entire website.
💻 Affected Systems
- WordPress Automatic Plugin
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete site takeover through administrative privilege escalation, data theft, malware injection, or site defacement.
Likely Case
Unauthorized configuration changes leading to SEO spam, malicious redirects, or backdoor installation.
If Mitigated
No impact if plugin is patched or removed, or if proper web application firewalls block exploitation attempts.
🎯 Exploit Status
Exploitation is straightforward via HTTP POST requests to process_form.php with crafted parameters.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.53.3 or later
Vendor Advisory: https://wordpress.org/plugins/wp-automatic/#developers
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins > Installed Plugins. 3. Find 'WordPress Automatic' and update to latest version. 4. Alternatively, deactivate and delete the plugin if not needed.
🔧 Temporary Workarounds
Block access to vulnerable file
allPrevent direct access to process_form.php via web server configuration.
For Apache: add 'Deny from all' to .htaccess in plugin directory
For Nginx: add 'location ~ process_form\.php$ { deny all; }' to site config
Web Application Firewall rule
allBlock requests to process_form.php containing suspicious parameter patterns.
🧯 If You Can't Patch
- Immediately deactivate and remove the WordPress Automatic Plugin from all sites.
- Implement strict network segmentation and monitor for unusual POST requests to process_form.php.
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin > Plugins > Installed Plugins for 'WordPress Automatic' version 3.53.2 or earlier.Check Version:
wp plugin list --name='WordPress Automatic' --field=version (if WP-CLI installed)Verify Fix Applied:
Confirm plugin version is 3.53.3 or later, or that plugin is removed.📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /wp-content/plugins/wp-automatic/process_form.php with parameter modifications
- Unusual WordPress option changes in database logs
Network Indicators:
- POST requests to process_form.php from unexpected IPs
- Sudden changes in site configuration or content
SIEM Query:
source="web_logs" AND uri="*process_form.php*" AND method="POST"🔗 References
- https://blog.nintechnet.com/critical-vulnerability-fixed-in-wordpress-automatic-plugin/
- https://www.wordfence.com/threat-intel/vulnerabilities/id/d0567dc8-7a4c-42f4-bf45-f31a8efaa354?source=cve
- https://blog.nintechnet.com/critical-vulnerability-fixed-in-wordpress-automatic-plugin/
- https://www.wordfence.com/threat-intel/vulnerabilities/id/d0567dc8-7a4c-42f4-bf45-f31a8efaa354?source=cve
