CVE-2024-23513: PropertyHive Deserialization Vulnerability

CVE-2024-23513 Overview

CVE-2024-23513 is a critical deserialization of untrusted data vulnerability affecting the PropertyHive WordPress plugin. This PHP Object Injection vulnerability allows unauthenticated remote attackers to inject malicious serialized objects into the application, potentially leading to remote code execution, data manipulation, or complete system compromise.

Critical Impact

Unauthenticated attackers can exploit this PHP Object Injection vulnerability to execute arbitrary code, compromise WordPress installations, and gain complete control over affected systems without any user interaction required.

Affected Products

• PropertyHive WordPress Plugin versions up to and including 2.0.5
• WordPress installations using vulnerable PropertyHive plugin versions
• wp-property-hive propertyhive

Discovery Timeline

• 2024-02-12 - CVE-2024-23513 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2024-23513

Vulnerability Analysis

This vulnerability stems from improper handling of serialized data within the PropertyHive WordPress plugin. PHP Object Injection occurs when user-controllable input is passed to PHP's unserialize() function without proper validation or sanitization. When an attacker can control the serialized string, they can instantiate arbitrary PHP objects, potentially triggering dangerous magic methods such as __wakeup(), __destruct(), or __toString().

The vulnerability is classified under CWE-502 (Deserialization of Untrusted Data), which represents one of the most severe classes of web application vulnerabilities. In the context of WordPress plugins, this type of flaw is particularly dangerous because the WordPress ecosystem often includes multiple plugins and themes with exploitable gadget chains that attackers can leverage.

Root Cause

The root cause of CVE-2024-23513 is the unsafe deserialization of user-supplied data within the PropertyHive plugin. The plugin fails to implement proper input validation before processing serialized objects, allowing attackers to craft malicious payloads that exploit the PHP object instantiation process. This architectural weakness violates the principle of never trusting user input, especially when dealing with complex data structures like serialized objects.

Attack Vector

The attack vector for this vulnerability is network-based and requires no authentication or user interaction. An attacker can exploit this vulnerability by sending specially crafted HTTP requests containing malicious serialized PHP objects to the affected WordPress installation.

The exploitation process typically involves:

1. Identifying endpoints that process serialized data in the PropertyHive plugin
2. Crafting a malicious serialized payload containing objects with dangerous magic methods
3. Sending the payload to the vulnerable endpoint via HTTP request
4. The application deserializes the malicious object, triggering code execution through gadget chains

Successful exploitation depends on the presence of suitable "gadget classes" within the WordPress installation that can be chained together to achieve code execution. Common WordPress installations frequently contain such gadget chains through core functionality, themes, or other installed plugins.

Detection Methods for CVE-2024-23513

Indicators of Compromise

• Unusual HTTP requests containing serialized PHP data (strings starting with O:, a:, or s:) targeting PropertyHive plugin endpoints
• Unexpected file creation or modification in WordPress directories
• Suspicious processes spawned by the web server user
• Anomalous database queries or modifications originating from deserialization-triggered code
• Web server logs showing requests with abnormally long parameter values containing serialized object notation

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block requests containing serialized PHP object patterns
• Monitor server logs for unusual activity patterns, particularly requests to PropertyHive plugin files
• Deploy file integrity monitoring to detect unauthorized changes to WordPress core, plugin, or theme files
• Enable PHP error logging to capture deserialization-related exceptions that may indicate exploitation attempts

Monitoring Recommendations

• Configure real-time alerting for requests containing PHP serialization patterns targeting the PropertyHive plugin
• Establish baseline behavior for WordPress installations and alert on deviations
• Monitor outbound network connections from the web server for potential reverse shell activity
• Review server access logs regularly for reconnaissance activity targeting plugin enumeration

How to Mitigate CVE-2024-23513

Immediate Actions Required

• Update PropertyHive plugin to the latest version immediately
• If immediate patching is not possible, consider temporarily disabling the PropertyHive plugin
• Audit WordPress installations to identify all instances running vulnerable versions
• Review server logs for any indicators of exploitation attempts

Patch Information

Organizations should update the PropertyHive WordPress plugin to a version newer than 2.0.5 to remediate this vulnerability. The latest patched version can be obtained from the official WordPress plugin repository. For detailed vulnerability information and remediation guidance, refer to the Patchstack Vulnerability Advisory.

Workarounds

• Implement WAF rules to block requests containing serialized PHP object patterns at the network perimeter
• Restrict access to the WordPress admin interface and plugin directories using IP-based access controls
• Consider using security plugins that provide virtual patching capabilities for known vulnerabilities
• Enable WordPress audit logging to track plugin activity and detect anomalous behavior

# Example WAF rule pattern for Apache mod_security
SecRule REQUEST_BODY "@rx O:\d+:\"[^\"]+\":\d+:" \
    "id:100001,phase:2,deny,status:403,msg:'Potential PHP Object Injection'"