CVE-2025-53499
📋 TL;DR
This CVE describes a missing authorization vulnerability in Wikimedia's MediaWiki 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 across the MediaWiki instance.
Likely Case
Unauthorized users bypass AbuseFilter restrictions to post prohibited content or perform actions that should be blocked by the filter system.
If Mitigated
With proper network segmentation and access controls, impact is 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 chains.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.43.2
Vendor Advisory: https://phabricator.wikimedia.org/T397196
Restart Required: No
Instructions:
1. Update the AbuseFilter extension to version 1.43.2 or later. 2. For MediaWiki installations: Navigate to extensions/AbuseFilter directory. 3. Run: git pull origin REL1_43 (or download and replace files). 4. No MediaWiki restart required, but clear caches if issues persist.
🔧 Temporary Workarounds
Disable AbuseFilter Extension
allTemporarily disable the vulnerable extension until patching is possible
Edit LocalSettings.php and comment out: wfLoadExtension('AbuseFilter');
Restrict Access via Web Server
linuxBlock access to AbuseFilter endpoints using web server configuration
For Apache: <Location "/w/index.php?title=Special:AbuseFilter"> Require valid-user </Location>
For Nginx: location ~* /w/index.php.*AbuseFilter { deny all; }
🧯 If You Can't Patch
- Implement strict network access controls to limit who can reach the MediaWiki instance
- Enable detailed logging for all AbuseFilter-related activities and monitor for unauthorized access attempts
🔍 How to Verify
Check if Vulnerable:
Check the AbuseFilter extension version in MediaWiki's Special:Version page or examine the extension's version file: cat extensions/AbuseFilter/extension.json | grep versionCheck Version:
grep -A2 '"version"' extensions/AbuseFilter/extension.jsonVerify Fix Applied:
Confirm version is 1.43.2 or higher via Special:Version page and test that unauthorized users cannot access AbuseFilter functionality📡 Detection & Monitoring
Log Indicators:
- Unauthorized access attempts to Special:AbuseFilter pages
- Unexpected modifications to AbuseFilter rules by non-administrative users
- Failed authorization checks in MediaWiki debug logs
Network Indicators:
- HTTP requests to /w/index.php?title=Special:AbuseFilter from unauthorized IPs
- POST requests to AbuseFilter API endpoints without proper authentication headers
SIEM Query:
source="mediawiki.log" AND (uri_path="*AbuseFilter*" OR uri_query="*AbuseFilter*") AND user="anonymous"