CVE-2025-67911
📋 TL;DR
This CVE describes a PHP object injection vulnerability in Tribulant Software's Newsletters WordPress plugin. Attackers can exploit insecure deserialization to execute arbitrary code on affected WordPress sites. All WordPress installations using Newsletters Lite plugin versions up to and including 4.11 are vulnerable.
💻 Affected Systems
- Tribulant Software Newsletters Lite WordPress Plugin
⚠️ 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
Remote code execution leading to complete system compromise, data theft, and website defacement.
Likely Case
Unauthenticated attackers gain shell access, install backdoors, and pivot to other systems.
If Mitigated
Attack limited to plugin directory if proper file permissions and web application firewalls are in place.
🎯 Exploit Status
Exploit requires sending specially crafted serialized data to vulnerable endpoints.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 4.12 or later
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins > Installed Plugins. 3. Find 'Newsletters Lite' and click 'Update Now'. 4. Verify version is 4.12 or higher.
🔧 Temporary Workarounds
Disable Plugin
allTemporarily disable the vulnerable plugin until patching is possible.
wp plugin deactivate newsletters-lite
Web Application Firewall Rule
allBlock requests containing serialized PHP objects to vulnerable endpoints.
ModSecurity rule: SecRule ARGS "@rx O:[0-9]+:" "id:1001,phase:2,deny,msg:'PHP Object Injection Attempt'"
🧯 If You Can't Patch
- Restrict network access to WordPress admin interface using IP whitelisting.
- Implement strict file permissions (755 for directories, 644 for files) and disable PHP execution in uploads directory.
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin panel > Plugins > Installed Plugins for Newsletters Lite version <= 4.11.Check Version:
wp plugin get newsletters-lite --field=versionVerify Fix Applied:
Confirm plugin version is 4.12 or higher in WordPress admin panel.📡 Detection & Monitoring
Log Indicators:
- POST requests to /wp-admin/admin-ajax.php with serialized data
- Unusual PHP process execution from web user
Network Indicators:
- HTTP requests containing serialized PHP objects (O:8:"stdClass":)
- Unexpected outbound connections from web server
SIEM Query:
source="web_logs" AND (uri="/wp-admin/admin-ajax.php" AND data MATCHES "O:[0-9]+:")