CVE-2024-49624: Advanced Advertising System Vulnerability

CVE-2024-49624 Overview

CVE-2024-49624 is a critical Deserialization of Untrusted Data vulnerability affecting the smartdevth Advanced Advertising System plugin for WordPress. This vulnerability allows unauthenticated attackers to perform PHP Object Injection attacks against vulnerable WordPress installations, potentially leading to complete site compromise.

Critical Impact

This PHP Object Injection vulnerability can be exploited remotely without authentication, enabling attackers to inject malicious serialized objects that could result in arbitrary code execution, data theft, or complete WordPress site takeover.

Affected Products

• smartdevth Advanced Advertising System versions up to and including 1.3.1
• WordPress installations running the vulnerable plugin versions
• All platforms running the affected WordPress plugin

Discovery Timeline

• 2024-10-20 - CVE-2024-49624 published to NVD
• 2026-04-01 - Last updated in NVD database

Technical Details for CVE-2024-49624

Vulnerability Analysis

This vulnerability stems from improper handling of serialized data within the Advanced Advertising System WordPress plugin. The plugin fails to properly validate or sanitize serialized input before passing it to PHP's deserialization functions, creating a classic PHP Object Injection attack surface.

In the context of WordPress, PHP Object Injection vulnerabilities are particularly dangerous because the WordPress ecosystem contains numerous classes with exploitable magic methods (__wakeup(), __destruct(), __toString(), etc.). When an attacker can control the serialized data being deserialized, they can instantiate arbitrary objects and manipulate the application's execution flow.

The network-accessible nature of this vulnerability means that remote attackers can exploit it without requiring any authentication or user interaction, significantly increasing the risk profile for affected WordPress sites.

Root Cause

The root cause of CVE-2024-49624 is the use of PHP's unserialize() function on untrusted user-controlled input without proper validation. The Advanced Advertising System plugin processes serialized data from external sources without implementing security controls such as:

• Input validation to verify the data format and expected content
• Whitelisting of allowed classes during deserialization
• Sanitization of serialized strings before processing

This allows attackers to craft malicious serialized payloads that instantiate dangerous PHP objects when deserialized by the application.

Attack Vector

The attack vector for this vulnerability is network-based, requiring no privileges or user interaction. An attacker can exploit this vulnerability by sending specially crafted HTTP requests containing malicious serialized PHP objects to the vulnerable WordPress plugin endpoints.

When the plugin deserializes the attacker-controlled input, it instantiates the malicious objects specified in the payload. If suitable gadget chains exist within the WordPress installation (through core WordPress classes, theme code, or other plugins), the attacker can achieve various malicious outcomes including:

• Remote code execution through POP (Property Oriented Programming) chains
• File operations such as reading sensitive configuration files
• SQL injection through object property manipulation
• Denial of service by triggering resource-intensive operations

The exploitation technique typically involves identifying available classes with exploitable magic methods and constructing a serialized payload that chains these classes together to achieve the desired malicious action.

Detection Methods for CVE-2024-49624

Indicators of Compromise

• Unusual HTTP requests containing serialized PHP object strings (patterns like O: followed by class names and properties)
• Web server access logs showing requests with base64-encoded or URL-encoded serialized payloads to plugin endpoints
• Unexpected file modifications or new files appearing in the WordPress installation directory
• Abnormal PHP process behavior or unexpected outbound network connections from the web server

Detection Strategies

• Monitor web application firewall (WAF) logs for serialization-related attack signatures and PHP object injection patterns
• Implement file integrity monitoring on WordPress core files, plugin directories, and configuration files
• Review web server access logs for suspicious requests targeting the advanced-advertising-system plugin paths
• Deploy runtime application self-protection (RASP) solutions capable of detecting deserialization attacks

Monitoring Recommendations

• Enable verbose logging for WordPress and the web server to capture detailed request information
• Configure security information and event management (SIEM) rules to alert on deserialization attack patterns
• Monitor for unexpected PHP process executions or shell spawning from web server processes
• Implement network traffic analysis to detect potential data exfiltration following exploitation attempts

How to Mitigate CVE-2024-49624

Immediate Actions Required

• Immediately disable or remove the Advanced Advertising System plugin version 1.3.1 and earlier from all WordPress installations
• Review WordPress installations for signs of compromise including unauthorized admin accounts, modified files, or suspicious database entries
• Implement web application firewall rules to block serialized PHP object payloads targeting the vulnerable plugin
• Audit access logs for evidence of exploitation attempts and initiate incident response procedures if compromise is detected

Patch Information

At the time of this analysis, users should consult the Patchstack Vulnerability Report for the latest information on available patches and security updates. If no patched version is available, removing the plugin entirely is strongly recommended until a security fix is released by the vendor.

Workarounds

• Remove or deactivate the Advanced Advertising System plugin until a patched version is available
• Implement web application firewall (WAF) rules to filter and block requests containing serialized PHP object patterns
• Use WordPress security plugins that provide runtime protection against object injection attacks
• Restrict access to WordPress admin and plugin functionality through IP whitelisting where feasible

If the plugin must remain active, consider implementing strict input validation at the web server level and monitoring all plugin-related traffic for malicious patterns. However, complete removal remains the most effective mitigation until an official patch is released.