CVE-2025-68531: ModelTheme Addons Object Injection Flaw

CVE-2025-68531 Overview

CVE-2025-68531 is a Deserialization of Untrusted Data vulnerability affecting the ModelTheme Addons for WPBakery and Elementor WordPress plugin. This security flaw allows authenticated attackers to perform PHP Object Injection attacks against vulnerable WordPress installations running affected versions of the plugin.

The vulnerability exists due to improper handling of serialized data, which can be exploited by attackers with low-level authentication to inject malicious PHP objects into the application. When combined with existing gadget chains in the WordPress ecosystem, this could lead to remote code execution, data exfiltration, or complete site compromise.

Critical Impact

Authenticated attackers can exploit this PHP Object Injection vulnerability to potentially achieve remote code execution, access sensitive data, or compromise the entire WordPress installation.

Affected Products

• ModelTheme Addons for WPBakery and Elementor versions prior to 1.5.6
• WordPress installations using the modeltheme-addons-for-wpbakery plugin
• Sites utilizing WPBakery or Elementor page builders with ModelTheme Addons

Discovery Timeline

• 2026-02-20 - CVE-2025-68531 published to NVD
• 2026-02-24 - Last updated in NVD database

Technical Details for CVE-2025-68531

Vulnerability Analysis

This vulnerability falls under CWE-502 (Deserialization of Untrusted Data), a well-documented vulnerability class that occurs when applications deserialize data from untrusted sources without proper validation. In the context of PHP applications like WordPress plugins, this typically manifests through the use of unserialize() on user-controlled input.

The ModelTheme Addons for WPBakery and Elementor plugin processes serialized data without adequate sanitization, allowing attackers to craft malicious serialized payloads. When these payloads are deserialized by the vulnerable plugin, they can instantiate arbitrary PHP objects with attacker-controlled properties.

The exploitation requires network access and low-privilege authentication (such as a subscriber or contributor role), but does not require user interaction. Successful exploitation can result in complete compromise of confidentiality, integrity, and availability of the affected WordPress installation.

Root Cause

The root cause of this vulnerability is the unsafe deserialization of user-supplied data within the ModelTheme Addons plugin. The plugin fails to implement proper input validation and sanitization before passing data to PHP's unserialize() function or similar deserialization mechanisms.

In PHP applications, when untrusted data is deserialized, attackers can manipulate the serialized string to instantiate objects of arbitrary classes. If these classes have magic methods like __wakeup(), __destruct(), or __toString() that perform sensitive operations, attackers can chain these methods (known as POP chains or gadget chains) to achieve malicious outcomes including file operations, database manipulation, or code execution.

Attack Vector

The attack vector is network-based, requiring the attacker to have authenticated access to the WordPress installation with at least subscriber-level privileges. The attack workflow involves:

1. The attacker authenticates to the WordPress site with minimal privileges
2. The attacker identifies an endpoint in the ModelTheme Addons plugin that processes serialized data
3. The attacker crafts a malicious serialized PHP object payload targeting known gadget chains
4. The payload is submitted to the vulnerable endpoint
5. The plugin deserializes the malicious payload, triggering the gadget chain
6. Depending on available gadget chains, this could result in arbitrary file writes, remote code execution, or other malicious actions

The lack of user interaction requirements and low complexity make this vulnerability relatively straightforward to exploit once an attacker has obtained basic authentication credentials.

Detection Methods for CVE-2025-68531

Indicators of Compromise

• Unusual serialized data patterns in HTTP request parameters or POST bodies containing PHP object notation (e.g., O:8:"stdClass")
• Unexpected file modifications or new files appearing in the WordPress installation
• Suspicious database entries containing serialized object data
• Authentication logs showing unusual activity from subscriber or contributor accounts

Detection Strategies

• Monitor web application logs for requests containing serialized PHP object patterns targeting ModelTheme Addons endpoints
• Implement Web Application Firewall (WAF) rules to detect and block serialized object injection attempts
• Use file integrity monitoring to detect unauthorized changes to WordPress core files, plugins, or themes
• Deploy runtime application security monitoring to detect deserialization operations on untrusted input

Monitoring Recommendations

• Enable verbose logging for the ModelTheme Addons plugin and review logs for anomalous deserialization activities
• Configure alerts for authentication events from low-privilege accounts followed by suspicious plugin interactions
• Implement network traffic analysis to identify potential data exfiltration following exploitation attempts

How to Mitigate CVE-2025-68531

Immediate Actions Required

• Update ModelTheme Addons for WPBakery and Elementor to version 1.5.6 or later immediately
• Review user accounts and remove unnecessary low-privilege users that could be leveraged for exploitation
• Audit recent activity logs for signs of exploitation attempts or successful compromise
• Consider temporarily disabling the plugin if immediate patching is not possible

Patch Information

The vulnerability has been addressed in ModelTheme Addons for WPBakery and Elementor version 1.5.6. WordPress administrators should update to this version or later through the WordPress plugin management interface or by downloading the patched version directly from the official source.

For detailed patch information and vulnerability specifics, refer to the Patchstack Vulnerability Report.

Workarounds

• Implement WAF rules to filter and block requests containing serialized PHP object patterns
• Restrict plugin access to administrator accounts only until the patch can be applied
• Use WordPress security plugins to add additional layers of input validation
• Consider implementing network-level access controls to limit who can authenticate to the WordPress admin area

# Example: Temporarily disable the vulnerable plugin via WP-CLI
wp plugin deactivate modeltheme-addons-for-wpbakery --path=/var/www/html/wordpress

# After updating, reactivate the plugin
wp plugin update modeltheme-addons-for-wpbakery --path=/var/www/html/wordpress
wp plugin activate modeltheme-addons-for-wpbakery --path=/var/www/html/wordpress