CVE-2025-49929
📋 TL;DR
This stored XSS vulnerability in the Ultimate Blocks WordPress plugin allows attackers to inject malicious scripts into web pages that persist and execute when other users view those pages. All WordPress sites using Ultimate Blocks version 3.3.6 or earlier are affected.
💻 Affected Systems
- Ultimate Blocks WordPress 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 admin credentials, deface websites, redirect users to malicious sites, or install backdoors for persistent access.
Likely Case
Attackers inject malicious scripts to steal user session cookies or credentials, potentially compromising user accounts.
If Mitigated
With proper input validation and output encoding, malicious scripts would be neutralized before execution.
🎯 Exploit Status
Requires attacker to have content creation privileges (like contributor or author role) to inject malicious scripts.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 3.3.7 or later
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Go to Plugins → Installed Plugins. 3. Find Ultimate Blocks and click 'Update Now'. 4. Verify update completes successfully.
🔧 Temporary Workarounds
Disable Ultimate Blocks Plugin
WordPressTemporarily disable the vulnerable plugin until patched
wp plugin deactivate ultimate-blocks
Restrict User Roles
WordPressLimit content creation to trusted users only
🧯 If You Can't Patch
- Implement Content Security Policy (CSP) headers to restrict script execution
- Use web application firewall (WAF) rules to block XSS payloads
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin → Plugins → Ultimate Blocks version numberCheck Version:
wp plugin get ultimate-blocks --field=versionVerify Fix Applied:
Verify Ultimate Blocks version is 3.3.7 or higher after update📡 Detection & Monitoring
Log Indicators:
- Unusual content modifications in posts/pages
- Suspicious script tags in database content
Network Indicators:
- Unexpected external script loads from WordPress pages
- Suspicious outbound connections after page views
SIEM Query:
source="wordpress" AND ("ultimate-blocks" OR "xss" OR "script injection")