CVE-2025-13839
📋 TL;DR
The LJUsers WordPress plugin has a stored cross-site scripting vulnerability that allows authenticated attackers with Contributor 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 LJUsers plugin versions up to 1.2.0 are affected.
💻 Affected Systems
- WordPress LJUsers 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 perform actions on behalf of authenticated users, potentially leading to complete site compromise.
Likely Case
Attackers with contributor access inject malicious scripts that steal user session cookies or credentials when visitors view affected pages, leading to account takeover.
If Mitigated
With proper input validation and output escaping, the vulnerability would be prevented, and only properly formatted data would be displayed.
🎯 Exploit Status
Exploitation requires authenticated access (Contributor role or higher). The vulnerability is in the 'name' parameter of the 'ljuser' shortcode.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.2.1 or later
Vendor Advisory: https://plugins.trac.wordpress.org/browser/ljusers
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find LJUsers plugin. 4. Click 'Update Now' if update available. 5. Alternatively, download version 1.2.1+ from WordPress plugin repository and replace existing files.
🔧 Temporary Workarounds
Disable LJUsers Plugin
allTemporarily disable the vulnerable plugin until patched
wp plugin deactivate ljusers
Remove Contributor Role Access
allRestrict plugin access to trusted users only
🧯 If You Can't Patch
- Implement web application firewall (WAF) rules to block XSS payloads in 'name' parameter
- Regularly audit user-generated content and monitor for suspicious script injections
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin panel → Plugins → Installed Plugins → LJUsers version. If version is 1.2.0 or lower, you are vulnerable.Check Version:
wp plugin get ljusers --field=versionVerify Fix Applied:
After updating, verify LJUsers plugin version is 1.2.1 or higher in WordPress admin panel.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to WordPress admin with script tags in parameters
- Multiple failed login attempts followed by successful contributor-level login
Network Indicators:
- HTTP requests containing malicious script payloads in 'name' parameter
- Outbound connections to suspicious domains after page views
SIEM Query:
source="wordpress.log" AND ("ljuser" OR "name parameter") AND ("script" OR "javascript:" OR "onerror=" OR "onload=")