CVE-2023-39311
📋 TL;DR
This CSRF vulnerability in ThemeFusion Fusion Builder allows attackers to trick authenticated WordPress administrators into performing unintended actions. It affects all WordPress sites using Fusion Builder plugin versions up to 3.11.1. Attackers could modify site content or settings without the admin's knowledge.
💻 Affected Systems
- ThemeFusion Fusion Builder
- Avada Builder
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could modify site content, inject malicious code, change settings, or perform administrative actions leading to site compromise or data leakage.
Likely Case
Attackers trick administrators into changing site content, adding malicious widgets, or modifying plugin settings that affect site functionality.
If Mitigated
With proper CSRF protections and admin awareness, impact is limited to unsuccessful attack attempts with no actual changes made.
🎯 Exploit Status
CSRF attacks are well-understood and easy to implement. Requires social engineering to trick authenticated users.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.11.2 or later
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins > Installed Plugins. 3. Find 'Fusion Builder' or 'Avada Builder'. 4. Click 'Update Now' if available. 5. Alternatively, download latest version from WordPress repository and manually update.
🔧 Temporary Workarounds
Implement CSRF Tokens
allAdd CSRF protection to WordPress forms and admin actions
Use Security Plugins
allInstall WordPress security plugins that provide CSRF protection
🧯 If You Can't Patch
- Restrict admin access to trusted networks only
- Implement strict SameSite cookie policies and use anti-CSRF browser extensions
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin panel > Plugins > Installed Plugins for Fusion Builder version. If version is 3.11.1 or lower, system is vulnerable.Check Version:
wp plugin list --name=fusion-builder --field=versionVerify Fix Applied:
After update, verify Fusion Builder version shows 3.11.2 or higher in WordPress plugins list.📡 Detection & Monitoring
Log Indicators:
- Unexpected admin actions from unusual IPs
- Multiple failed CSRF token validations
- Admin actions without corresponding user interaction logs
Network Indicators:
- POST requests to admin-ajax.php or admin-post.php without proper referrer headers
- Requests with missing or invalid nonce parameters
SIEM Query:
source="wordpress.log" AND ("admin-ajax.php" OR "admin-post.php") AND NOT referer="*wp-admin*"🔗 References
- https://patchstack.com/database/vulnerability/fusion-builder/wordpress-avada-builder-plugin-3-11-1-cross-site-request-forgery-csrf-vulnerability?_s_id=cve
- https://patchstack.com/database/vulnerability/fusion-builder/wordpress-avada-builder-plugin-3-11-1-cross-site-request-forgery-csrf-vulnerability?_s_id=cve
