CVE-2021-4370
📋 TL;DR
The uListing WordPress plugin up to version 1.6.6 has an authorization bypass vulnerability where unauthenticated users can access administrative actions and endpoints. This occurs due to missing security nonces and insufficient data validation. Any WordPress site using the vulnerable plugin versions is affected.
💻 Affected Systems
- WordPress uListing plugin
📦 What is this software?
Ulisting by Stylemixthemes
⚠️ Risk & Real-World Impact
Worst Case
Complete site compromise - attackers could modify content, inject malicious code, create admin accounts, or delete the entire site.
Likely Case
Unauthorized content modification, data theft, or malware injection leading to SEO spam, credential harvesting, or site defacement.
If Mitigated
Limited impact with proper network segmentation and web application firewalls blocking suspicious administrative requests.
🎯 Exploit Status
The vulnerability is straightforward to exploit - attackers can simply send HTTP requests to administrative endpoints without authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.6.7 and later
Vendor Advisory: https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=2456786%40ulisting&new=2456786%40ulisting&sfp_email=&sfph_mail=
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find uListing plugin. 4. Click 'Update Now' if available. 5. Alternatively, download version 1.6.7+ from WordPress.org and manually update.
🔧 Temporary Workarounds
Disable uListing Plugin
allTemporarily disable the vulnerable plugin until patched
wp plugin deactivate ulisting
Web Application Firewall Rules
linuxBlock access to uListing administrative endpoints
# Example mod_security rule: SecRule REQUEST_URI "@contains /wp-admin/admin-ajax.php?action=ulisting_" "id:1001,phase:2,deny,status:403,msg:'Block uListing admin actions'"
🧯 If You Can't Patch
- Implement strict network access controls to limit who can access the WordPress admin interface
- Deploy a web application firewall with rules blocking suspicious requests to uListing endpoints
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin → Plugins → Installed Plugins for uListing version. If version is 1.6.6 or lower, you are vulnerable.Check Version:
wp plugin get ulisting --field=versionVerify Fix Applied:
Verify uListing plugin version is 1.6.7 or higher in WordPress admin panel.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /wp-admin/admin-ajax.php with ulisting_ actions from unauthenticated IPs
- Multiple 403 errors from blocked uListing endpoint access attempts
Network Indicators:
- HTTP requests to uListing administrative endpoints from external IPs without prior authentication
SIEM Query:
source="web_logs" AND uri="/wp-admin/admin-ajax.php" AND query="*ulisting_*" AND NOT user_agent="*bot*" | stats count by src_ip🔗 References
- https://blog.nintechnet.com/wordpress-ulisting-plugin-fixed-multiple-critical-vulnerabilities/
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=2456786%40ulisting&new=2456786%40ulisting&sfp_email=&sfph_mail=
- https://www.wordfence.com/threat-intel/vulnerabilities/id/c5ada976-03b8-4219-9ae3-9060fb7b9de5?source=cve
- https://blog.nintechnet.com/wordpress-ulisting-plugin-fixed-multiple-critical-vulnerabilities/
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=2456786%40ulisting&new=2456786%40ulisting&sfp_email=&sfph_mail=
- https://www.wordfence.com/threat-intel/vulnerabilities/id/c5ada976-03b8-4219-9ae3-9060fb7b9de5?source=cve
