CVE-2021-24889
📋 TL;DR
This SQL injection vulnerability in the Ninja Forms Contact Form WordPress plugin allows authenticated administrators to execute arbitrary SQL commands. It affects WordPress sites running Ninja Forms versions before 3.6.4, potentially leading to data theft, modification, or complete database compromise.
💻 Affected Systems
- Ninja Forms Contact Form WordPress Plugin
📦 What is this software?
Ninja Forms by Ninjaforms
⚠️ Risk & Real-World Impact
Worst Case
Complete database compromise including sensitive user data, admin credential theft, and potential site takeover via privilege escalation.
Likely Case
Data exfiltration of form submissions, user information, and potentially other WordPress database content.
If Mitigated
Limited impact due to proper access controls and monitoring detecting unusual admin activity.
🎯 Exploit Status
Exploitation requires authenticated admin access. Public proof-of-concept exists demonstrating SQL injection via fields parameter.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.6.4
Vendor Advisory: https://wpscan.com/vulnerability/55008a42-eb56-436c-bce0-10ee616d0495
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find Ninja Forms plugin. 4. Click 'Update Now' if update available. 5. If no update shows, manually download version 3.6.4+ from WordPress.org.
🔧 Temporary Workarounds
Temporary Plugin Deactivation
allDisable the vulnerable plugin until patched
wp plugin deactivate ninja-forms
Admin Access Restriction
allTemporarily restrict admin panel access to trusted IPs only
🧯 If You Can't Patch
- Implement strict principle of least privilege for WordPress admin accounts
- Enable database query logging and monitor for unusual SQL patterns
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin panel → Plugins → Ninja Forms version numberCheck Version:
wp plugin get ninja-forms --field=versionVerify Fix Applied:
Confirm Ninja Forms version is 3.6.4 or higher in WordPress admin📡 Detection & Monitoring
Log Indicators:
- Unusual SQL queries in WordPress/database logs
- Multiple admin-level form submissions with unusual parameters
Network Indicators:
- POST requests to /wp-admin/admin-ajax.php with fields parameter containing SQL syntax
SIEM Query:
source="wordpress.log" AND "admin-ajax.php" AND "fields=" AND ("SELECT" OR "UNION" OR "INSERT" OR "UPDATE")