CVE-2025-49330: Zoho CRM Integration Object Injection Flaw

CVE-2025-49330 Overview

CVE-2025-49330 is a critical PHP Object Injection vulnerability affecting the CRM Perks Integration for Contact Form 7 and Zoho CRM, Bigin WordPress plugin. The vulnerability stems from insecure deserialization of untrusted data, allowing unauthenticated attackers to inject arbitrary PHP objects into the application. When combined with existing gadget chains in the WordPress ecosystem, this vulnerability can lead to remote code execution, data exfiltration, or complete site compromise.

Critical Impact

Unauthenticated attackers can exploit this PHP Object Injection vulnerability to potentially achieve remote code execution, modify sensitive data, or take complete control of affected WordPress installations.

Affected Products

• Integration for Contact Form 7 and Zoho CRM, Bigin versions up to and including 1.3.0
• WordPress installations using the cf7-zoho plugin
• Websites integrating Contact Form 7 with Zoho CRM services

Discovery Timeline

• 2025-06-17 - CVE-2025-49330 published to NVD
• 2025-06-17 - Last updated in NVD database

Technical Details for CVE-2025-49330

Vulnerability Analysis

This vulnerability is classified as CWE-502 (Deserialization of Untrusted Data), a well-documented weakness that occurs when an application deserializes data from untrusted sources without proper validation. In the context of this WordPress plugin, user-supplied input is passed to PHP's unserialize() function without adequate sanitization.

PHP Object Injection vulnerabilities are particularly dangerous in WordPress environments due to the presence of numerous class libraries that can serve as "gadget chains." When an attacker controls the serialized data being deserialized, they can instantiate arbitrary objects with attacker-controlled properties. If suitable gadget classes exist that perform dangerous operations in their magic methods (__wakeup(), __destruct(), __toString(), etc.), the attacker can chain these to achieve code execution or other malicious outcomes.

The vulnerability requires no authentication and can be exploited remotely via network access, making it particularly severe. Successful exploitation could allow attackers to execute arbitrary PHP code, read or modify database contents, upload malicious files, or pivot to attack other systems on the network.

Root Cause

The root cause of this vulnerability is the unsafe handling of serialized PHP data within the plugin. The Integration for Contact Form 7 and Zoho CRM plugin fails to validate or sanitize user-controlled input before passing it to the unserialize() function. Modern PHP security best practices recommend avoiding unserialize() on untrusted data entirely, instead using safer alternatives like json_encode()/json_decode() or implementing strict allowlists for acceptable classes using the allowed_classes option introduced in PHP 7.0.

Attack Vector

The attack vector is network-based, requiring no user interaction or prior authentication. An attacker can craft a malicious serialized PHP payload and submit it through the vulnerable input channels exposed by the plugin. The attack flow typically involves:

1. Identifying the vulnerable endpoint that processes serialized data
2. Analyzing available classes in the WordPress installation for suitable gadget chains
3. Crafting a serialized payload that instantiates objects with malicious property values
4. Submitting the payload to trigger deserialization and execute the gadget chain

The vulnerability is exploited by crafting a malicious serialized PHP object that, when deserialized, triggers dangerous operations through magic methods. Common exploitation techniques involve leveraging existing WordPress core or plugin classes that contain exploitable magic methods. For detailed technical analysis, refer to the Patchstack vulnerability database entry.

Detection Methods for CVE-2025-49330

Indicators of Compromise

• Unusual PHP serialized data patterns in web server access logs containing object injection signatures (e.g., O: followed by class names)
• Unexpected file creation or modification in WordPress directories, particularly in wp-content/uploads or plugin directories
• Anomalous database queries or modifications related to the cf7-zoho plugin tables
• Web application firewall logs showing blocked serialization-related payloads

Detection Strategies

• Deploy web application firewall (WAF) rules to detect and block PHP serialized object patterns in HTTP requests
• Monitor WordPress error logs for deserialization-related PHP errors or warnings
• Implement file integrity monitoring on WordPress core files, plugin directories, and critical configuration files
• Analyze HTTP request payloads for characteristic PHP serialization patterns (a:, O:, s: prefixes)

Monitoring Recommendations

• Enable verbose logging on the WordPress installation and review logs for suspicious plugin activity
• Configure SIEM alerts for PHP Object Injection attack signatures in web traffic
• Monitor outbound network connections from the web server for potential data exfiltration or C2 communications
• Implement real-time alerting for any new file creation or code modifications in plugin directories

How to Mitigate CVE-2025-49330

Immediate Actions Required

• Update the Integration for Contact Form 7 and Zoho CRM, Bigin plugin to a patched version immediately if available
• Temporarily disable the cf7-zoho plugin if no patch is available until a security update is released
• Implement WAF rules to block requests containing PHP serialized object patterns
• Review web server and WordPress logs for any signs of exploitation attempts

Patch Information

Organizations should check for updated versions of the Integration for Contact Form 7 and Zoho CRM, Bigin plugin that address this vulnerability. Monitor the official WordPress plugin repository and the Patchstack security advisory for patch availability. Until a patch is released, consider the workarounds listed below.

Workarounds

• Disable the vulnerable plugin entirely until a security patch is released
• Implement web application firewall rules to filter and block PHP serialization patterns in incoming requests
• Restrict network access to the WordPress admin and plugin endpoints using IP allowlisting where feasible
• Enable WordPress security plugins that provide runtime protection against object injection attacks

# ModSecurity WAF rule to block PHP serialized objects
SecRule REQUEST_BODY "@rx O:\d+:\"[^\"]+\":\d+:{" \
    "id:1001,phase:2,deny,status:403,msg:'PHP Object Injection Attempt Blocked'"