CVE-2025-39363
📋 TL;DR
This stored XSS vulnerability in the Custom Login and Registration WordPress plugin allows attackers to inject malicious scripts into web pages. When users view affected pages, the scripts execute in their browsers, potentially stealing credentials or session cookies. All WordPress sites using vulnerable versions of this plugin are affected.
💻 Affected Systems
- Custom Login and Registration WordPress plugin
📦 What is this software?
Custom Login And Registration by Alphaefficiencyteam
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator credentials, take over websites, deface content, or distribute malware to visitors.
Likely Case
Attackers steal user session cookies or credentials, potentially compromising user accounts and performing unauthorized actions.
If Mitigated
With proper input validation and output encoding, malicious scripts would be neutralized before reaching users.
🎯 Exploit Status
XSS vulnerabilities are commonly exploited, though specific exploit details for this CVE aren't publicly documented.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after 1.0.0
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins > Installed Plugins. 3. Find 'Custom Login and Registration'. 4. If update is available, click 'Update Now'. 5. If no update is available, disable or remove the plugin.
🔧 Temporary Workarounds
Disable vulnerable plugin
allTemporarily disable the Custom Login and Registration plugin until a patched version is available.
wp plugin deactivate custom-login-and-registration
Implement Content Security Policy
allAdd CSP headers to restrict script execution sources and mitigate XSS impact.
Add 'Content-Security-Policy: default-src 'self'' to web server configuration
🧯 If You Can't Patch
- Implement web application firewall (WAF) rules to block XSS payloads
- Enable input validation and output encoding in application code
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin panel > Plugins > Installed Plugins for 'Custom Login and Registration' version 1.0.0 or earlier.Check Version:
wp plugin get custom-login-and-registration --field=versionVerify Fix Applied:
Verify plugin version is greater than 1.0.0 in WordPress admin panel.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to login/registration endpoints with script tags
- Multiple failed login attempts followed by successful ones
Network Indicators:
- HTTP requests containing <script> tags in parameters
- Outbound connections to suspicious domains after login
SIEM Query:
source="web_server_logs" AND (uri_path="/wp-login.php" OR uri_path="/wp-admin/") AND (http_method="POST") AND (user_agent CONTAINS "script" OR referer CONTAINS "javascript:")