CVE-2025-53495
📋 TL;DR
This CVE describes a Missing Authorization vulnerability in MediaWiki's AbuseFilter extension that allows unauthorized users to bypass access controls. It affects MediaWiki installations with the AbuseFilter extension enabled, specifically versions from 1.43.X before 1.43.2. Attackers could potentially modify filter rules or access restricted functionality without proper authentication.
💻 Affected Systems
- Wikimedia MediaWiki AbuseFilter Extension
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Unauthorized attackers could modify AbuseFilter rules to disable security protections, allow malicious content, or escalate privileges within the MediaWiki instance.
Likely Case
Unauthorized users could bypass AbuseFilter restrictions to post prohibited content, evade spam filters, or perform actions that should be restricted to administrators.
If Mitigated
With proper network segmentation and minimal user privileges, impact would be limited to the AbuseFilter functionality rather than full system compromise.
🎯 Exploit Status
The vulnerability involves missing authorization checks, which typically means simple HTTP requests can trigger the issue without complex exploitation techniques.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.43.2
Vendor Advisory: https://phabricator.wikimedia.org/T396750
Restart Required: No
Instructions:
1. Update MediaWiki AbuseFilter extension to version 1.43.2 or later. 2. For MediaWiki installations: Update via composer or download from official repository. 3. Verify the update by checking extension version in Special:Version page.
🔧 Temporary Workarounds
Disable AbuseFilter Extension
allTemporarily disable the vulnerable extension until patching is possible
Edit LocalSettings.php and comment out or remove: wfLoadExtension('AbuseFilter');
Restrict Access via Web Server
linuxUse web server configuration to restrict access to AbuseFilter functionality
Add access control rules in Apache/Nginx to restrict /w/index.php?title=Special:AbuseFilter paths
🧯 If You Can't Patch
- Implement strict network access controls to limit who can access the MediaWiki instance
- Enable detailed logging for AbuseFilter actions and monitor for unauthorized access attempts
🔍 How to Verify
Check if Vulnerable:
Check MediaWiki version and AbuseFilter extension version via Special:Version page. If AbuseFilter version is between 1.43.0 and 1.43.1, the system is vulnerable.Check Version:
php maintenance/run.php ./extensions/AbuseFilter/maintenance/checkVersion.phpVerify Fix Applied:
After updating, verify AbuseFilter extension version shows 1.43.2 or higher on Special:Version page. Test authorization by attempting unauthorized access to AbuseFilter functions.📡 Detection & Monitoring
Log Indicators:
- Unauthorized access attempts to AbuseFilter special pages
- Unexpected modifications to AbuseFilter rules by non-admin users
- Failed authorization checks in MediaWiki logs
Network Indicators:
- HTTP requests to /w/index.php?title=Special:AbuseFilter from unauthorized IPs
- Unusual pattern of requests to AbuseFilter API endpoints
SIEM Query:
source="mediawiki.log" AND ("Special:AbuseFilter" OR "AbuseFilter") AND (user!="admin" OR user="*" OR auth_failure)