CVE-2025-8621
📋 TL;DR
The Mosaic Generator WordPress plugin has a stored XSS vulnerability that allows authenticated attackers with Contributor-level access or higher to inject malicious scripts into website pages. These scripts execute whenever users view the compromised pages, potentially stealing credentials or performing unauthorized actions. All WordPress sites using Mosaic Generator version 1.0.5 or earlier are affected.
💻 Affected Systems
- WordPress Mosaic Generator 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, deface websites, redirect users to malicious sites, or install backdoors for persistent access.
Likely Case
Attackers with contributor accounts inject malicious scripts to steal user session cookies or credentials, potentially escalating privileges.
If Mitigated
With proper access controls and input validation, impact is limited to isolated script execution without significant data compromise.
🎯 Exploit Status
Requires authenticated access (Contributor role or higher) and knowledge of vulnerable parameter.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version after 1.0.5
Vendor Advisory: https://wordpress.org/plugins/mosaic-generator/#developers
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find Mosaic Generator and click 'Update Now'. 4. Verify plugin version is higher than 1.0.5.
🔧 Temporary Workarounds
Disable vulnerable plugin
allTemporarily deactivate Mosaic Generator plugin until patched
wp plugin deactivate mosaic-generator
Restrict user roles
allTemporarily remove Contributor role access or limit to trusted users only
🧯 If You Can't Patch
- Implement web application firewall (WAF) rules to block XSS payloads in 'c' parameter
- Monitor and audit user accounts with Contributor role or higher for suspicious activity
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin panel → Plugins → Installed Plugins → Mosaic Generator versionCheck Version:
wp plugin get mosaic-generator --field=versionVerify Fix Applied:
Verify plugin version is higher than 1.0.5 and test parameter sanitization📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests containing script tags in 'c' parameter
- Multiple page edits by Contributor-level users
Network Indicators:
- HTTP requests with encoded script payloads in query parameters
SIEM Query:
source="wordpress.log" AND "mosaic-generator" AND ("<script>" OR "javascript:" OR "onerror=" OR "onload=")