CVE-2025-3439
📋 TL;DR
The Everest Forms WordPress plugin is vulnerable to PHP object injection via deserialization of untrusted input in the 'field_value' parameter. This allows unauthenticated attackers to inject PHP objects, but impact requires another plugin/theme with a POP chain to be present. All WordPress sites using Everest Forms versions up to 3.1.1 are affected.
💻 Affected Systems
- Everest Forms WordPress Plugin
📦 What is this software?
Everest Forms by Wpeverest
⚠️ Risk & Real-World Impact
Worst Case
If combined with a POP chain from another plugin/theme, attackers could achieve remote code execution, file deletion, or data exfiltration.
Likely Case
No impact unless another vulnerable plugin/theme with exploitable POP chain is installed on the same WordPress instance.
If Mitigated
With proper patch management and minimal plugin installations, risk is limited to denial of service or minor disruption.
🎯 Exploit Status
Exploitation requires finding or crafting a suitable POP chain from other installed components.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 3.1.2 or later
Vendor Advisory: https://plugins.trac.wordpress.org/changeset/3268742/
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find Everest Forms and click 'Update Now'. 4. Verify update to version 3.1.2 or higher.
🔧 Temporary Workarounds
Disable Everest Forms Plugin
allTemporarily disable the vulnerable plugin until patched
wp plugin deactivate everest-forms
Web Application Firewall Rule
allBlock requests containing suspicious field_value parameters
🧯 If You Can't Patch
- Remove Everest Forms plugin completely if not essential
- Implement strict WAF rules to block PHP object injection patterns
🔍 How to Verify
Check if Vulnerable:
Check Everest Forms plugin version in WordPress admin panel under Plugins → Installed PluginsCheck Version:
wp plugin get everest-forms --field=versionVerify Fix Applied:
Confirm Everest Forms version is 3.1.2 or higher after update📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to Everest Forms endpoints with field_value parameter
- PHP deserialization errors in web server logs
Network Indicators:
- HTTP POST requests containing serialized PHP object patterns in field_value parameter
SIEM Query:
web_requests WHERE url_path CONTAINS 'everest-forms' AND post_data CONTAINS 'field_value' AND post_data MATCHES 'O:[0-9]+:'