CVE-2025-60210: Everest Forms Deserialization Vulnerability

CVE-2025-60210 Overview

CVE-2025-60210 is a critical Deserialization of Untrusted Data vulnerability affecting the Everest Forms - Frontend Listing WordPress plugin developed by wpeverest. This security flaw allows attackers to perform PHP Object Injection attacks against vulnerable WordPress installations running affected versions of the plugin.

The vulnerability exists due to improper handling of serialized data, enabling unauthenticated attackers to inject malicious PHP objects. When combined with suitable gadget chains present in the WordPress environment, this can lead to complete site compromise including remote code execution, data theft, or full system takeover.

Critical Impact

Unauthenticated attackers can exploit this Object Injection vulnerability to potentially achieve remote code execution, compromise sensitive data, or gain complete control over affected WordPress sites.

Affected Products

• Everest Forms - Frontend Listing plugin versions up to and including 1.0.5
• WordPress installations running the vulnerable plugin versions
• All sites using wpeverest Everest Forms Frontend Listing without security patches

Discovery Timeline

• 2025-10-22 - CVE-2025-60210 published to NVD
• 2026-01-20 - Last updated in NVD database

Technical Details for CVE-2025-60210

Vulnerability Analysis

This vulnerability falls under CWE-502 (Deserialization of Untrusted Data), a dangerous class of security flaws that occurs when applications deserialize data from untrusted sources without proper validation. In the context of the Everest Forms - Frontend Listing plugin, the vulnerability allows attackers to inject arbitrary PHP objects through unvalidated user input.

PHP Object Injection vulnerabilities are particularly dangerous in WordPress environments due to the rich ecosystem of plugins and themes that may contain exploitable "magic methods" such as __wakeup(), __destruct(), or __toString(). When a malicious serialized object is passed to PHP's unserialize() function, these magic methods can be triggered, potentially leading to arbitrary code execution.

The network-accessible nature of this vulnerability means that attackers can exploit it remotely without requiring any prior authentication or user interaction, significantly increasing the risk to affected systems.

Root Cause

The root cause of this vulnerability stems from the plugin's improper handling of serialized PHP data. The Everest Forms - Frontend Listing plugin fails to adequately validate or sanitize user-supplied input before passing it to deserialization functions. This allows attackers to craft malicious serialized payloads that, when deserialized by the application, instantiate arbitrary PHP objects with attacker-controlled properties.

The lack of input validation combined with the use of PHP's native unserialize() function on untrusted data creates the conditions necessary for successful exploitation.

Attack Vector

The attack vector for CVE-2025-60210 is network-based, requiring no authentication or user interaction. An attacker can exploit this vulnerability by:

1. Identifying a WordPress site running a vulnerable version of Everest Forms - Frontend Listing (<= 1.0.5)
2. Crafting a malicious serialized PHP object payload targeting available gadget chains
3. Submitting the payload through the vulnerable input vector
4. The application deserializes the malicious object, triggering the attack chain

The exploitation complexity is low, as the attacker simply needs to deliver a properly crafted serialized payload to the vulnerable endpoint. When combined with Property Oriented Programming (POP) chains from common WordPress components, this can result in remote code execution.

For detailed technical information about this vulnerability, refer to the Patchstack WordPress Vulnerability Report.

Detection Methods for CVE-2025-60210

Indicators of Compromise

• Unusual PHP serialized data in web server access logs, particularly containing object notation like O: followed by class names
• Unexpected file creation or modification in WordPress directories
• Suspicious POST requests to Everest Forms endpoints containing serialized payloads
• Web application firewall alerts for deserialization attack patterns

Detection Strategies

• Implement web application firewall rules to detect and block serialized PHP object patterns in HTTP requests
• Monitor server logs for requests containing suspicious serialized data structures (e.g., patterns matching O:[0-9]+:")
• Deploy file integrity monitoring on WordPress core files, plugin directories, and theme folders
• Use WordPress security plugins to scan for known vulnerability signatures

Monitoring Recommendations

• Enable detailed access logging on web servers to capture full request bodies for forensic analysis
• Configure alerting for any modifications to PHP files within the WordPress installation
• Monitor for new user account creation, especially administrator accounts
• Implement real-time log analysis to detect exploitation attempts against form submission endpoints

How to Mitigate CVE-2025-60210

Immediate Actions Required

• Immediately update Everest Forms - Frontend Listing to a patched version if available
• If no patch is available, consider temporarily deactivating the plugin until a security fix is released
• Implement web application firewall rules to block serialized PHP object payloads
• Review WordPress site for signs of compromise and restore from clean backups if necessary
• Audit all installed plugins and themes for additional deserialization vulnerabilities

Patch Information

Organizations should monitor the official wpeverest channels and the WordPress plugin repository for security updates addressing this vulnerability. The Patchstack WordPress Vulnerability Report provides additional details about the affected versions and remediation guidance.

Ensure automatic updates are enabled for WordPress plugins, or establish a process for rapid deployment of security patches when they become available.

Workarounds

• Temporarily disable or remove the Everest Forms - Frontend Listing plugin if it is not critical to site functionality
• Implement strict input validation at the web server or WAF level to reject requests containing PHP serialized objects
• Use a security plugin like Wordfence or Sucuri to add an additional layer of protection against exploitation attempts
• Consider implementing application-level restrictions to limit the functionality exposed by the vulnerable plugin

# Example: Block PHP serialized object patterns in Apache .htaccess
# Add to WordPress root .htaccess file
<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteCond %{QUERY_STRING} (O:[0-9]+:") [NC,OR]
    RewriteCond %{REQUEST_BODY} (O:[0-9]+:") [NC]
    RewriteRule .* - [F,L]
</IfModule>