CVE-2025-69079: ThemeREX Musicplace Deserialization Flaw

CVE-2025-69079 Overview

CVE-2025-69079 is a Deserialization of Untrusted Data vulnerability affecting the ThemeREX Sound | Musical Instruments Online Store WordPress theme (musicplace). This vulnerability allows attackers to perform Object Injection attacks by exploiting insecure deserialization of user-controlled data. Object Injection vulnerabilities in PHP applications can lead to serious consequences including remote code execution, authentication bypass, and arbitrary file manipulation.

Critical Impact

Successful exploitation could allow attackers to inject malicious objects into the application, potentially leading to remote code execution, data theft, or complete site compromise.

Affected Products

• ThemeREX Sound | Musical Instruments Online Store (musicplace) theme versions up to and including 1.6.9
• WordPress installations running the vulnerable musicplace theme

Discovery Timeline

• 2026-01-22 - CVE CVE-2025-69079 published to NVD
• 2026-01-22 - Last updated in NVD database

Technical Details for CVE-2025-69079

Vulnerability Analysis

This vulnerability falls under CWE-502 (Deserialization of Untrusted Data), which occurs when an application deserializes data from untrusted sources without proper validation. In the context of WordPress themes, this typically manifests when user-supplied input is passed to PHP's unserialize() function without adequate sanitization.

PHP Object Injection vulnerabilities are particularly dangerous because they can be chained with existing classes in the application (known as "gadget chains") to achieve various malicious outcomes. When a serialized object is passed to unserialize(), PHP automatically invokes magic methods such as __wakeup(), __destruct(), or __toString() on the reconstructed object, which can be leveraged by attackers to execute arbitrary code or perform other malicious actions.

Root Cause

The root cause of this vulnerability is the use of PHP's unserialize() function on untrusted user input within the musicplace theme. The theme fails to implement proper input validation and sanitization before deserializing data, allowing attackers to craft malicious serialized payloads. WordPress themes that process serialized data from user input, cookies, or database values without validation are susceptible to this class of vulnerability.

Attack Vector

An attacker can exploit this vulnerability by crafting a malicious serialized PHP object and submitting it through a vulnerable input vector in the musicplace theme. The attack does not require authentication and can be performed remotely. The malicious payload is constructed to instantiate objects from classes available in the WordPress ecosystem, triggering dangerous magic methods that can lead to:

• Remote code execution through existing gadget chains
• Arbitrary file read/write operations
• SQL injection via object properties
• Authentication bypass
• Denial of service

The exploitation typically involves identifying usable gadget chains within WordPress core, installed plugins, or the theme itself. Tools like PHPGGC can be used to generate payloads for known gadget chains.

Detection Methods for CVE-2025-69079

Indicators of Compromise

• Unusual serialized data patterns in HTTP request parameters, particularly containing O: (object) notation
• Web server logs showing requests with base64-encoded or URL-encoded serialized PHP objects
• Unexpected file modifications or new files created in the WordPress installation
• Unusual database entries containing serialized object data
• Error logs showing PHP unserialization warnings or class instantiation errors

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect serialized PHP object patterns in incoming requests
• Monitor for requests containing serialization markers such as O:, a:, s: in unusual parameters
• Implement file integrity monitoring to detect unauthorized changes to theme and plugin files
• Review web server access logs for suspicious payloads targeting theme-specific endpoints

Monitoring Recommendations

• Enable verbose logging for the WordPress installation to capture detailed request information
• Implement real-time alerting for detection of serialized object patterns in HTTP traffic
• Monitor system processes for unexpected PHP child processes that may indicate successful code execution
• Regularly audit user sessions and authentication logs for anomalies

How to Mitigate CVE-2025-69079

Immediate Actions Required

• Update the ThemeREX Sound | Musical Instruments Online Store (musicplace) theme to a patched version if available
• If no patch is available, consider temporarily disabling or replacing the vulnerable theme
• Implement WAF rules to block requests containing serialized PHP objects
• Review server logs for any signs of exploitation attempts

Patch Information

Refer to the Patchstack WordPress Vulnerability Report for the latest patch information and updates from the vendor. Contact ThemeREX for information about patched versions of the musicplace theme.

Workarounds

• Implement input validation at the application level to reject serialized data in user input
• Use json_encode()/json_decode() instead of PHP serialization where possible
• Deploy a Web Application Firewall with rules to block PHP object injection attempts
• Restrict file system permissions to limit the impact of potential code execution
• Consider using PHP's allowed_classes parameter with unserialize() if the theme code can be modified

# Example WAF rule for ModSecurity to detect PHP object injection
SecRule REQUEST_URI|ARGS|REQUEST_BODY "@rx O:\d+:\"[^\"]+\":\d+:" \
    "id:100001,\
    phase:2,\
    deny,\
    status:403,\
    log,\
    msg:'PHP Object Injection Attempt Detected',\
    tag:'application-multi',\
    tag:'language-php',\
    tag:'platform-multi',\
    tag:'attack-injection-php'"