CVE-2024-13742: iControlWP PHP Object Injection Flaw

CVE-2024-13742 Overview

The iControlWP – Multiple WordPress Site Manager plugin for WordPress contains a PHP Object Injection vulnerability in all versions up to and including 4.4.5. The vulnerability exists due to insecure deserialization of untrusted input from the reqpars parameter. This flaw allows unauthenticated attackers to inject arbitrary PHP objects into the application.

While no known POP (Property Oriented Programming) chain is present in the vulnerable plugin itself, the exploitation potential increases significantly when other plugins or themes with exploitable POP chains are installed on the same WordPress site. If such a chain exists, attackers may be able to delete arbitrary files, retrieve sensitive data, or achieve remote code execution.

Critical Impact

Unauthenticated attackers can exploit this PHP Object Injection vulnerability to potentially achieve remote code execution, arbitrary file deletion, or sensitive data exfiltration when combined with POP chains from other installed plugins or themes.

Affected Products

• iControlWP – Multiple WordPress Site Manager plugin versions up to and including 4.4.5
• WordPress installations using the iControlWP plugin
• WordPress multisite environments managed through iControlWP

Discovery Timeline

• 2025-01-30 - CVE CVE-2024-13742 published to NVD
• 2025-01-30 - Last updated in NVD database

Technical Details for CVE-2024-13742

Vulnerability Analysis

This vulnerability is classified as CWE-502 (Deserialization of Untrusted Data). The iControlWP plugin processes user-supplied input through the reqpars parameter without proper validation or sanitization before passing it to PHP's deserialization functions.

PHP Object Injection vulnerabilities occur when applications deserialize user-controlled data using functions like unserialize(). When an attacker can control the serialized data, they can instantiate arbitrary objects with attacker-controlled property values. The security impact depends on the availability of "magic methods" (such as __wakeup(), __destruct(), or __toString()) in loaded classes that can be chained together to form a POP gadget chain.

The vulnerability can be exploited remotely over the network without requiring any authentication or user interaction. If a compatible POP chain exists in the WordPress installation (from other plugins or themes), an attacker could leverage this to achieve full system compromise.

Root Cause

The root cause of this vulnerability is the use of PHP's unserialize() function on untrusted user input without implementing proper input validation or using safer alternatives like json_decode(). The vulnerable code paths can be found in the RequestParameters.php file within both the legacy API and the main API directories.

The plugin fails to:

1. Validate the input format before deserialization
2. Implement allowlisting for acceptable classes during unserialization
3. Use PHP 7's allowed_classes option to restrict deserializable objects

Attack Vector

The attack vector is network-based and requires no authentication or privileges. An attacker can craft a malicious serialized PHP object and send it via the reqpars parameter to the vulnerable endpoint. The attack flow proceeds as follows:

1. Attacker identifies a WordPress site running the vulnerable iControlWP plugin
2. Attacker enumerates installed plugins/themes to find potential POP gadgets
3. Attacker crafts a serialized PHP object payload targeting available gadget chains
4. The malicious payload is sent to the vulnerable endpoint via the reqpars parameter
5. The server deserializes the payload, instantiating the attacker-controlled objects
6. Magic methods trigger the POP chain, executing the attacker's intended actions

For technical details on the vulnerable code paths, see the WordPress Plugin Code Review and WordPress Plugin Source Code.

Detection Methods for CVE-2024-13742

Indicators of Compromise

• Unusual HTTP requests containing serialized PHP objects in the reqpars parameter
• Unexpected file modifications or deletions on the WordPress server
• Web server logs showing malformed or base64-encoded serialized data in request parameters
• Unexplained database modifications or data exfiltration patterns

Detection Strategies

• Monitor web application firewall (WAF) logs for serialized PHP object patterns (e.g., O: followed by class names)
• Implement intrusion detection rules to identify unserialize() exploitation attempts
• Review access logs for unusual POST requests to iControlWP plugin endpoints
• Deploy file integrity monitoring to detect unauthorized changes to WordPress files

Monitoring Recommendations

• Configure real-time alerting for requests containing PHP serialization signatures
• Enable verbose logging on WordPress installations using iControlWP
• Monitor for unusual outbound connections that may indicate successful exploitation
• Implement behavioral analysis to detect post-exploitation activities such as webshell deployment

How to Mitigate CVE-2024-13742

Immediate Actions Required

• Update the iControlWP plugin to a version newer than 4.4.5 that addresses this vulnerability
• If an update is not immediately available, consider temporarily disabling the iControlWP plugin
• Review installed plugins and themes for potential POP chain gadgets
• Audit WordPress installation for signs of compromise

Patch Information

Organizations should monitor the WordPress plugin repository and the vendor's official channels for security updates addressing this vulnerability. The Wordfence Vulnerability Report provides additional information and tracking for this issue.

Workarounds

• Implement a Web Application Firewall (WAF) rule to block requests containing serialized PHP objects in the reqpars parameter
• Restrict access to WordPress admin and plugin endpoints through IP allowlisting
• Remove or disable the iControlWP plugin until an official patch is released
• Reduce the attack surface by removing unused plugins and themes that may contain POP chain gadgets

# Configuration example - Apache .htaccess rule to block serialized object patterns
<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteCond %{QUERY_STRING} reqpars.*O:[0-9]+ [NC,OR]
    RewriteCond %{REQUEST_BODY} reqpars.*O:[0-9]+ [NC]
    RewriteRule .* - [F,L]
</IfModule>