CVE-2024-56058: VRPConnector Object Injection Vulnerability

CVE-2024-56058 Overview

CVE-2024-56058 is a Deserialization of Untrusted Data vulnerability affecting the VRPConnector WordPress plugin developed by denniskravetstns. This vulnerability allows attackers to perform PHP Object Injection attacks, potentially leading to remote code execution, unauthorized data access, or complete site compromise.

Critical Impact

PHP Object Injection vulnerabilities can be chained with existing gadget chains in WordPress or other installed plugins to achieve arbitrary code execution, data manipulation, or complete server compromise.

Affected Products

• VRPConnector WordPress Plugin versions up to and including 2.0.1

Discovery Timeline

• 2024-12-18 - CVE-2024-56058 published to NVD
• 2026-04-01 - Last updated in NVD database

Technical Details for CVE-2024-56058

Vulnerability Analysis

This vulnerability stems from CWE-502: Deserialization of Untrusted Data. The VRPConnector plugin fails to properly validate or sanitize serialized data before passing it to PHP's unserialize() function. When user-controlled input reaches deserialization routines without proper validation, attackers can craft malicious serialized payloads that instantiate arbitrary PHP objects.

PHP Object Injection attacks exploit the magic methods in PHP classes (such as __wakeup(), __destruct(), __toString(), etc.) that are automatically invoked during the deserialization process. By carefully constructing serialized payloads that reference classes with exploitable magic methods (known as "gadget chains"), attackers can trigger unintended code paths.

Root Cause

The root cause of this vulnerability is the unsafe use of PHP's unserialize() function on user-supplied input without proper validation or restriction of allowed classes. The VRPConnector plugin likely processes serialized data from external sources (such as form submissions, API calls, or database entries) and deserializes this data without implementing security controls like using unserialize() with the allowed_classes option set to false or a whitelist of safe classes.

Attack Vector

Attackers can exploit this vulnerability by supplying crafted serialized PHP objects to the vulnerable plugin endpoints. The attack requires identifying an entry point where serialized data is processed and constructing a payload that leverages available gadget chains within the WordPress installation or other installed plugins.

The exploitation typically follows this pattern:

1. Identify a user-controllable input that reaches unserialize()
2. Enumerate available classes with exploitable magic methods
3. Craft a serialized payload utilizing these gadget chains
4. Submit the payload to achieve the desired malicious outcome (RCE, file manipulation, etc.)

For detailed technical information about this vulnerability, refer to the Patchstack Security Advisory.

Detection Methods for CVE-2024-56058

Indicators of Compromise

• Unusual serialized data patterns in web server access logs, particularly containing PHP object notation (O:, a:, s:)
• Unexpected file modifications or new files created in the WordPress installation directory
• Anomalous outbound network connections from the web server
• Error logs showing class instantiation failures or unexpected object destructor calls

Detection Strategies

• Monitor web application firewall (WAF) logs for serialized PHP object patterns in request parameters
• Implement file integrity monitoring on WordPress core files and plugin directories
• Review access logs for suspicious POST requests to VRPConnector endpoints
• Deploy runtime application self-protection (RASP) solutions to detect deserialization attacks

Monitoring Recommendations

• Enable detailed PHP error logging to capture failed deserialization attempts
• Configure intrusion detection systems (IDS) to alert on PHP serialization patterns in HTTP traffic
• Implement centralized log aggregation for WordPress installations to correlate attack attempts
• Monitor for new user account creation or privilege escalation events that may indicate successful exploitation

How to Mitigate CVE-2024-56058

Immediate Actions Required

• Disable or remove the VRPConnector plugin (vrpconnector) immediately if it is not essential
• Audit your WordPress installation for signs of compromise
• Review all plugins for similar deserialization vulnerabilities
• Implement a Web Application Firewall (WAF) with rules to block serialized PHP object payloads

Patch Information

As of the last update, all versions of VRPConnector up to and including 2.0.1 are affected. Check the Patchstack Security Advisory for the latest information on available patches or updated plugin versions.

Workarounds

• Remove the VRPConnector plugin entirely if functionality is not required
• Implement WAF rules to filter requests containing PHP serialized object patterns
• Use PHP's disable_functions directive to restrict dangerous functions that gadget chains commonly exploit
• Apply the principle of least privilege to the WordPress database user to limit post-exploitation impact

# Example WAF rule pattern for ModSecurity to block PHP serialization attacks
# Add to your ModSecurity configuration
SecRule REQUEST_BODY "@rx O:\d+:\"[a-zA-Z_]" \
    "id:1001,\
    phase:2,\
    deny,\
    status:403,\
    msg:'Potential PHP Object Injection Attack',\
    tag:'CVE-2024-56058'"