CVE-2021-24814
📋 TL;DR
This vulnerability in the WordPress GDPR plugin allows cross-site scripting (XSS) attacks through a misconfigured AJAX endpoint. Both unauthenticated and authenticated users can exploit it to execute JavaScript in victims' browsers. If an administrator with a valid session is targeted, attackers can gain full control of the WordPress instance.
💻 Affected Systems
- WordPress GDPR plugin
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of WordPress instance through administrator session hijacking, allowing data theft, defacement, backdoor installation, and further network penetration.
Likely Case
Session hijacking of logged-in users, credential theft, content manipulation, and potential privilege escalation to administrator.
If Mitigated
Limited to reflected XSS with no session compromise if proper content security policies and input validation are implemented.
🎯 Exploit Status
Exploitation requires tricking a victim into visiting a malicious link. The vulnerability is well-documented with public proof-of-concept available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.9.26
Vendor Advisory: https://wpscan.com/vulnerability/94ab34f6-86a9-4e14-bf86-26ff6cb4383e
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find 'GDPR' plugin. 4. Click 'Update Now' if update is available. 5. Alternatively, download version 1.9.26+ from WordPress repository and manually update.
🔧 Temporary Workarounds
Disable vulnerable AJAX endpoint
allRemove or restrict access to the check_privacy_settings AJAX action
Add to theme's functions.php or custom plugin: remove_action('wp_ajax_check_privacy_settings', 'gdpr_check_privacy_settings'); remove_action('wp_ajax_nopriv_check_privacy_settings', 'gdpr_check_privacy_settings');
Content Security Policy header
linuxImplement CSP to prevent script execution from unauthorized sources
Add to .htaccess: Header set Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline';"
🧯 If You Can't Patch
- Disable the GDPR plugin completely until patched
- Implement web application firewall rules to block requests to /wp-admin/admin-ajax.php?action=check_privacy_settings
🔍 How to Verify
Check if Vulnerable:
Check plugin version in WordPress admin panel under Plugins → Installed Plugins. If GDPR plugin version is below 1.9.26, it's vulnerable.Check Version:
wp plugin list --name=gdpr --field=versionVerify Fix Applied:
Verify plugin version is 1.9.26 or higher. Test the endpoint at /wp-admin/admin-ajax.php?action=check_privacy_settings to ensure it returns proper Content-Type header.📡 Detection & Monitoring
Log Indicators:
- Multiple requests to /wp-admin/admin-ajax.php with action=check_privacy_settings
- Unusual JavaScript payloads in query parameters
- Requests from suspicious IPs to the AJAX endpoint
Network Indicators:
- HTTP requests with malicious JavaScript in parameters targeting the vulnerable endpoint
- Unusual traffic patterns to admin-ajax.php
SIEM Query:
source="web_logs" AND uri_path="/wp-admin/admin-ajax.php" AND query_string="*action=check_privacy_settings*"