CVE-2021-24550
📋 TL;DR
This vulnerability allows authenticated attackers to perform SQL injection attacks in the Broken Link Manager WordPress plugin. Attackers can manipulate database queries through the unsanitized 'url' GET parameter when editing links. WordPress sites using vulnerable plugin versions are affected.
💻 Affected Systems
- Broken Link Manager WordPress Plugin
📦 What is this software?
Broken Link Manager by Broken Link Manager Project
⚠️ Risk & Real-World Impact
Worst Case
Complete database compromise allowing data theft, modification, or deletion; potential privilege escalation to administrator access; possible remote code execution if database permissions allow.
Likely Case
Unauthorized data access and extraction from the WordPress database, including user credentials, sensitive content, and configuration data.
If Mitigated
Limited impact with proper input validation and parameterized queries preventing SQL injection.
🎯 Exploit Status
Exploitation requires authenticated user access; SQL injection techniques are well-documented and easily automated.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.6.6 or later
Vendor Advisory: https://wordpress.org/plugins/broken-link-manager/#developers
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find Broken Link Manager. 4. Click 'Update Now' if available. 5. Alternatively, delete and reinstall latest version from WordPress repository.
🔧 Temporary Workarounds
Disable Plugin
allTemporarily disable the vulnerable plugin until patched
wp plugin deactivate broken-link-manager
WAF Rule
linuxImplement web application firewall rules to block SQL injection attempts
ModSecurity rule: SecRule ARGS_GET:url "@detectSQLi" "id:1001,phase:2,deny"
🧯 If You Can't Patch
- Restrict plugin access to trusted administrators only
- Implement network segmentation to isolate WordPress instance
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin panel → Plugins → Broken Link Manager version; if version ≤0.6.5, vulnerable.Check Version:
wp plugin get broken-link-manager --field=versionVerify Fix Applied:
Confirm plugin version is ≥0.6.6 in WordPress admin panel.📡 Detection & Monitoring
Log Indicators:
- Unusual SQL queries in database logs
- Multiple failed authentication attempts followed by SQL-like patterns in URL parameters
- wp-content/plugins/broken-link-manager/ requests with SQL syntax in URL parameters
Network Indicators:
- HTTP GET requests to edit.php?page=broken-link-manager&url= containing SQL keywords (UNION, SELECT, etc.)
SIEM Query:
source="web_logs" AND uri="*broken-link-manager*" AND (uri="*UNION*" OR uri="*SELECT*" OR uri="*INSERT*" OR uri="*DELETE*")