CVE-2025-32927: Foodbakery Object Injection Vulnerability

CVE-2025-32927 Overview

A critical deserialization of untrusted data vulnerability has been identified in the FoodBakery WordPress plugin by Chimpstudio. This PHP Object Injection vulnerability allows attackers to exploit insecure deserialization mechanisms, potentially leading to remote code execution, data manipulation, or complete site compromise. The vulnerability affects FoodBakery versions through 3.3 and can be exploited remotely without authentication.

Critical Impact

Unauthenticated attackers can inject malicious serialized objects that, when deserialized by the application, may result in arbitrary code execution, complete WordPress site takeover, or sensitive data exfiltration.

Affected Products

• FoodBakery WordPress Plugin (versions up to and including 3.3)
• WordPress installations running vulnerable FoodBakery plugin
• Sites using Chimpgroup FoodBakery theme/plugin ecosystem

Discovery Timeline

• 2025-05-19 - CVE CVE-2025-32927 published to NVD
• 2025-05-29 - Last updated in NVD database

Technical Details for CVE-2025-32927

Vulnerability Analysis

This vulnerability stems from CWE-502 (Deserialization of Untrusted Data), a well-documented security weakness where applications deserialize user-controlled data without proper validation. In the context of the FoodBakery plugin, the application processes serialized PHP objects from untrusted sources, allowing attackers to craft malicious payloads that execute arbitrary operations upon deserialization.

PHP Object Injection vulnerabilities in WordPress plugins are particularly dangerous because WordPress's extensive codebase and common libraries often contain "gadget chains" - sequences of class methods that can be exploited when triggered by deserialized objects. An attacker can leverage these existing classes to perform malicious actions such as file operations, database queries, or system command execution.

Root Cause

The root cause of this vulnerability lies in the FoodBakery plugin's improper handling of serialized data. The application uses PHP's unserialize() function on user-controllable input without implementing adequate validation or sanitization. When the unserialize() function processes attacker-controlled data, it instantiates objects and invokes magic methods such as __wakeup(), __destruct(), or __toString(), which can be chained together to achieve arbitrary code execution.

Attack Vector

The attack can be executed remotely over the network without requiring authentication or user interaction. An attacker identifies input vectors where serialized data is processed by the plugin, then crafts a malicious serialized PHP object payload. When this payload is submitted to the vulnerable endpoint and deserialized by the application, the malicious object's methods are invoked, executing the attacker's intended operations.

The exploitation typically involves:

1. Identifying a deserialization entry point in the FoodBakery plugin
2. Analyzing available PHP classes for exploitable gadget chains
3. Constructing a serialized payload that chains vulnerable class methods
4. Submitting the payload to trigger deserialization and code execution

For detailed technical information about this vulnerability, refer to the Patchstack security advisory.

Detection Methods for CVE-2025-32927

Indicators of Compromise

• Unexpected serialized data patterns in web server access logs (look for O: or a: patterns in POST data)
• Unusual PHP error logs indicating object instantiation failures or unexpected class invocations
• New or modified files in the WordPress installation directory with suspicious content
• Unauthorized WordPress administrator accounts or modified user privileges
• Database anomalies including unexpected entries or modified site options

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block serialized PHP object patterns in HTTP requests
• Implement file integrity monitoring on WordPress core files, plugin directories, and theme files
• Configure intrusion detection systems to alert on suspicious PHP deserialization patterns
• Monitor for unexpected outbound connections from the web server that may indicate reverse shell establishment

Monitoring Recommendations

• Enable verbose logging for the FoodBakery plugin and review logs for deserialization-related errors
• Set up real-time alerting for WordPress configuration changes or new user account creation
• Monitor web server access logs for unusual POST request patterns targeting plugin endpoints
• Implement baseline monitoring for expected WordPress file checksums and alert on modifications

How to Mitigate CVE-2025-32927

Immediate Actions Required

• Update the FoodBakery plugin to a patched version immediately if one is available from Chimpstudio
• If no patch is available, consider temporarily disabling the FoodBakery plugin until a fix is released
• Review WordPress user accounts for any unauthorized additions and remove suspicious accounts
• Scan the WordPress installation for malware or unauthorized modifications using security plugins
• Implement additional WAF rules to block potential object injection payloads

Patch Information

Organizations using the FoodBakery WordPress plugin should check for updates through the WordPress plugin repository or directly from Chimpstudio. The vulnerability affects all versions through 3.3, so updating to a version that addresses this issue is critical. Monitor the Patchstack vulnerability database for updated remediation guidance.

Workarounds

• Implement WAF rules to filter requests containing serialized PHP object patterns (O:[0-9]+:, a:[0-9]+:)
• Restrict access to the WordPress admin area and plugin endpoints using IP allowlisting
• Use WordPress security plugins that provide object injection protection capabilities
• Consider placing the site in maintenance mode while awaiting an official patch if business operations permit

# Apache .htaccess WAF rule to block common PHP object injection patterns
<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteCond %{REQUEST_METHOD} POST
    RewriteCond %{THE_REQUEST} (O:[0-9]+:|a:[0-9]+:) [NC]
    RewriteRule .* - [F,L]
</IfModule>