CVE-2025-31394
📋 TL;DR
This stored cross-site scripting (XSS) vulnerability in the WordPress More Mime Type Filters plugin allows attackers to inject malicious scripts that execute when other users view affected pages. The vulnerability affects all WordPress sites using this plugin from any version up to 0.3. Attackers can steal session cookies, redirect users, or perform actions on their behalf.
💻 Affected Systems
- WordPress More Mime Type Filters plugin
⚠️ 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
Attackers could steal administrator credentials, take over the WordPress site, install backdoors, deface the website, or use the compromised site to attack visitors.
Likely Case
Attackers inject malicious JavaScript to steal user session cookies, redirect users to phishing sites, or perform unauthorized actions on behalf of logged-in users.
If Mitigated
With proper input validation and output encoding, malicious scripts would be neutralized before reaching users, preventing execution.
🎯 Exploit Status
Stored XSS vulnerabilities are commonly exploited. While no public PoC is confirmed, the vulnerability type is well-understood and weaponization is likely.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.4 or later
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find 'More Mime Type Filters'. 4. Click 'Update Now' if available. 5. If no update appears, deactivate and delete the plugin, then install version 0.4+ from WordPress repository.
🔧 Temporary Workarounds
Disable vulnerable plugin
allTemporarily deactivate the More Mime Type Filters plugin until patched
wp plugin deactivate more-mime-type-filters
Implement Content Security Policy
allAdd CSP headers to restrict script execution sources
Add to .htaccess: Header set Content-Security-Policy "default-src 'self'; script-src 'self'"
Add to wp-config.php: header("Content-Security-Policy: default-src 'self'; script-src 'self'");
🧯 If You Can't Patch
- Disable the More Mime Type Filters plugin immediately
- Implement web application firewall (WAF) rules to block XSS payloads
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin → Plugins → Installed Plugins for 'More Mime Type Filters' version 0.3 or earlierCheck Version:
wp plugin get more-mime-type-filters --field=versionVerify Fix Applied:
Verify plugin version is 0.4 or later in WordPress admin panel📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to plugin endpoints
- Suspicious JavaScript in form submissions
- Multiple failed XSS attempts in web server logs
Network Indicators:
- Malicious script tags in HTTP requests
- Unusual outbound connections after page views
- Suspicious referrer headers
SIEM Query:
source="web_logs" AND ("more-mime-type-filters" OR "mime_type_filters") AND ("script" OR "javascript" OR "onload" OR "onerror")