CVE-2021-24581
📋 TL;DR
This vulnerability in the Blue Admin WordPress plugin allows attackers to inject malicious scripts into the 'Logo Title' setting, which then executes when users view affected pages. Attackers can exploit this via Cross-Site Request Forgery (CSRF) since the plugin lacks CSRF protection. WordPress sites using vulnerable versions of Blue Admin are affected.
💻 Affected Systems
- Blue Admin WordPress Plugin
📦 What is this software?
Blue Admin by Blue Admin Project
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator session cookies, redirect users to malicious sites, deface websites, or perform actions as authenticated users, potentially leading to complete site compromise.
Likely Case
Attackers inject malicious JavaScript to steal user session cookies or credentials, perform unauthorized actions, or redirect users to phishing sites.
If Mitigated
With proper input validation, output encoding, and CSRF tokens, the vulnerability would be prevented entirely.
🎯 Exploit Status
Exploitation requires tricking an administrator into performing an action (CSRF) or having some level of access. The XSS payload executes in the context of users viewing the affected page.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 21.06.02 or later
Vendor Advisory: https://wpscan.com/vulnerability/75abd073-b45f-4fe6-8501-7a6d0163f78d
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins > Installed Plugins. 3. Find Blue Admin plugin. 4. Click 'Update Now' if available. 5. Alternatively, download latest version from WordPress repository and replace plugin files.
🔧 Temporary Workarounds
Disable Blue Admin Plugin
linuxTemporarily disable the vulnerable plugin until patched
wp plugin deactivate blue-admin
Implement WAF Rules
allAdd web application firewall rules to block XSS payloads in POST requests to admin-ajax.php or plugin settings pages
🧯 If You Can't Patch
- Remove Blue Admin plugin entirely if not needed
- Implement strict Content Security Policy (CSP) headers to mitigate XSS impact
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin > Plugins > Installed Plugins for Blue Admin version. If version is 21.06.01 or earlier, you are vulnerable.Check Version:
wp plugin get blue-admin --field=versionVerify Fix Applied:
After updating, verify Blue Admin version is 21.06.02 or later in WordPress plugins list.📡 Detection & Monitoring
Log Indicators:
- POST requests to admin-ajax.php with suspicious script tags in parameters
- Unusual modifications to Blue Admin plugin settings
Network Indicators:
- HTTP requests containing script tags or JavaScript in POST parameters to WordPress admin endpoints
SIEM Query:
source="wordpress.log" AND ("admin-ajax.php" OR "blue-admin") AND ("<script>" OR "javascript:" OR "onerror=" OR "onload=")