CVE-2023-3388
📋 TL;DR
This vulnerability allows unauthenticated attackers to inject malicious JavaScript into WordPress sites using the Beautiful Cookie Consent Banner plugin. When users visit pages containing the injected script, it executes in their browsers, potentially stealing cookies, session tokens, or performing other malicious actions. All WordPress sites running vulnerable plugin versions are affected.
💻 Affected Systems
- Beautiful Cookie Consent Banner for WordPress
📦 What is this software?
Beautiful Cookie Consent Banner by Beautiful Cookie Banner
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator session cookies, take over WordPress sites, deface websites, redirect users to malicious sites, or install backdoors for persistent access.
Likely Case
Attackers inject malicious scripts to steal user session cookies, redirect visitors to phishing pages, or display unwanted advertisements.
If Mitigated
With proper web application firewalls and input validation, the attack would be blocked before reaching vulnerable code.
🎯 Exploit Status
The vulnerability was actively exploited in large-scale campaigns as reported by Wordfence. Attackers can exploit this without authentication by sending specially crafted requests to vulnerable sites.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.10.2
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find 'Beautiful Cookie Consent Banner'. 4. Click 'Update Now' if available. 5. If no update appears, manually download version 2.10.2+ from WordPress.org and replace the plugin files.
🔧 Temporary Workarounds
Disable vulnerable plugin
allTemporarily disable the Beautiful Cookie Consent Banner plugin until patched
wp plugin deactivate beautiful-and-responsive-cookie-consent
Web Application Firewall rule
allBlock requests containing malicious script patterns in the nsc_bar_content_href parameter
🧯 If You Can't Patch
- Implement strict Content Security Policy (CSP) headers to prevent script execution from untrusted sources
- Deploy a web application firewall (WAF) with XSS protection rules enabled
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin → Plugins → Installed Plugins for Beautiful Cookie Consent Banner version. If version is 2.10.1 or lower, you are vulnerable.Check Version:
wp plugin get beautiful-and-responsive-cookie-consent --field=versionVerify Fix Applied:
After updating, verify the plugin version shows 2.10.2 or higher in WordPress admin panel.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to WordPress admin-ajax.php with nsc_bar_content_href parameter containing script tags
- Multiple failed XSS attempts in web server logs
Network Indicators:
- HTTP requests with JavaScript payloads in URL parameters
- Unusual traffic patterns to cookie consent plugin endpoints
SIEM Query:
source="web_server_logs" AND ("nsc_bar_content_href" AND ("<script" OR "javascript:" OR "onerror="))🔗 References
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=2857982%40beautiful-and-responsive-cookie-consent&new=2857982%40beautiful-and-responsive-cookie-consent&sfp_email=&sfph_mail=
- https://www.wordfence.com/blog/2023/05/wordfence-firewall-blocks-bizarre-large-scale-xss-campaign/
- https://www.wordfence.com/threat-intel/vulnerabilities/id/542a4079-b1a2-49bc-9ddd-ba7978c9992e?source=cve
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=2857982%40beautiful-and-responsive-cookie-consent&new=2857982%40beautiful-and-responsive-cookie-consent&sfp_email=&sfph_mail=
- https://www.wordfence.com/blog/2023/05/wordfence-firewall-blocks-bizarre-large-scale-xss-campaign/
- https://www.wordfence.com/threat-intel/vulnerabilities/id/542a4079-b1a2-49bc-9ddd-ba7978c9992e?source=cve
