CVE-2025-11975
📋 TL;DR
The FuseWP WordPress plugin has an authorization bypass vulnerability that allows unauthenticated attackers to modify sync rules between WordPress users and email marketing platforms. This affects all WordPress sites using FuseWP plugin versions 1.1.23.0 and earlier. Attackers can manipulate how user data flows to services like Mailchimp, Constant Contact, and ActiveCampaign.
💻 Affected Systems
- FuseWP – WordPress User Sync to Email List & Marketing Automation
⚠️ 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 create malicious sync rules that exfiltrate sensitive user data to attacker-controlled email lists, modify existing rules to disrupt legitimate marketing automation, or potentially chain with other vulnerabilities for further compromise.
Likely Case
Attackers will add or modify sync rules to harvest user email addresses and personal data to spam lists, potentially violating data protection regulations and damaging brand reputation.
If Mitigated
With proper web application firewalls and monitoring, unauthorized rule changes would be detected and blocked before causing data exfiltration.
🎯 Exploit Status
The vulnerability requires no authentication and involves simple HTTP requests to the vulnerable endpoint.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version after 1.1.23.0
Vendor Advisory: https://plugins.trac.wordpress.org/changeset/3383939/fusewp/trunk/src/core/src/Admin/SettingsPage/SyncPage.php
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find FuseWP plugin. 4. Click 'Update Now' if available, or manually update to latest version. 5. Verify plugin is updated to version beyond 1.1.23.0.
🔧 Temporary Workarounds
Disable FuseWP Plugin
allTemporarily disable the vulnerable plugin until patched
wp plugin deactivate fusewp
Web Application Firewall Rule
allBlock access to the vulnerable save_changes() function endpoint
Block POST requests to /wp-admin/admin-ajax.php with action parameter containing 'fusewp_save_changes'
🧯 If You Can't Patch
- Disable the FuseWP plugin immediately
- Implement strict WAF rules blocking all admin-ajax.php requests to the FuseWP plugin endpoints
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin → Plugins → Installed Plugins for FuseWP version. If version is 1.1.23.0 or lower, you are vulnerable.Check Version:
wp plugin get fusewp --field=versionVerify Fix Applied:
After updating, verify FuseWP plugin version is higher than 1.1.23.0 in WordPress admin panel.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /wp-admin/admin-ajax.php with 'fusewp_save_changes' action parameter from unauthenticated IPs
- Multiple sync rule modifications in short timeframes
Network Indicators:
- HTTP POST requests to admin-ajax.php with fusewp-related parameters from external IPs without authentication cookies
SIEM Query:
source="web_logs" AND uri="/wp-admin/admin-ajax.php" AND method="POST" AND (params.action="fusewp_save_changes" OR params.action CONTAINS "fusewp") AND NOT (cookie CONTAINS "wordpress_logged_in" OR auth_status="success")