CVE-2025-49507: CozyStay Object Injection Vulnerability

CVE-2025-49507 Overview

A critical deserialization of untrusted data vulnerability has been identified in the LoftOcean CozyStay WordPress theme. This PHP Object Injection vulnerability allows attackers to inject malicious serialized objects into the application, potentially leading to remote code execution, data manipulation, or complete site compromise. The vulnerability affects all versions of CozyStay prior to version 1.7.1.

Critical Impact

Unauthenticated attackers can exploit this PHP Object Injection vulnerability to execute arbitrary code, manipulate data, or gain complete control over affected WordPress installations.

Affected Products

• LoftOcean CozyStay WordPress Theme versions prior to 1.7.1

Discovery Timeline

• 2025-06-10 - CVE-2025-49507 published to NVD
• 2025-06-12 - Last updated in NVD database

Technical Details for CVE-2025-49507

Vulnerability Analysis

This vulnerability falls under CWE-502 (Deserialization of Untrusted Data), a well-documented weakness where an application accepts serialized data from untrusted sources without proper validation. In the context of the CozyStay WordPress theme, the application processes user-controlled serialized PHP data, enabling attackers to craft malicious payloads that exploit the PHP unserialization mechanism.

PHP Object Injection vulnerabilities are particularly dangerous in WordPress environments due to the availability of numerous "magic methods" and POP (Property-Oriented Programming) chains within WordPress core and popular plugins. When a malicious serialized object is deserialized, PHP automatically invokes magic methods such as __wakeup(), __destruct(), or __toString(), allowing attackers to trigger arbitrary functionality within the application's codebase.

Root Cause

The root cause of this vulnerability is the insecure handling of serialized data within the CozyStay theme. The application fails to properly validate or sanitize serialized input before passing it to PHP's unserialize() function. This allows attackers to inject arbitrary PHP objects with malicious property values, which are then instantiated by the application during the deserialization process.

Attack Vector

This vulnerability is exploitable over the network without requiring authentication or user interaction. An attacker can craft a malicious HTTP request containing a specially crafted serialized PHP object payload. When the CozyStay theme processes this request and deserializes the payload, the attacker's object is instantiated with attacker-controlled properties.

The exploitation typically involves identifying gadget chains within the WordPress ecosystem—sequences of class methods that can be chained together to achieve code execution. Attackers craft serialized objects that, when deserialized, trigger these gadget chains to execute arbitrary PHP code, write files to the filesystem, or perform other malicious actions.

For detailed technical information about this vulnerability, refer to the Patchstack Vulnerability Report.

Detection Methods for CVE-2025-49507

Indicators of Compromise

• Presence of unusual serialized data patterns in HTTP request logs (look for strings starting with O: or a: followed by numeric values)
• Unexpected file creation or modification in WordPress directories
• Anomalous PHP process execution or system command invocations
• Error logs containing PHP unserialization warnings or object instantiation failures

Detection Strategies

• Monitor web server access logs for requests containing serialized PHP object patterns in POST data, cookies, or URL parameters
• Implement Web Application Firewall (WAF) rules to detect and block common PHP serialization attack patterns
• Deploy file integrity monitoring on WordPress installations to detect unauthorized changes
• Review PHP error logs for unserialization-related warnings that may indicate exploitation attempts

Monitoring Recommendations

• Enable verbose logging on WordPress installations to capture detailed request information
• Configure security monitoring tools to alert on suspicious patterns indicative of object injection attacks
• Establish baseline behavior for the CozyStay theme and monitor for deviations
• Implement network traffic analysis to identify unusual outbound connections from WordPress servers

How to Mitigate CVE-2025-49507

Immediate Actions Required

• Update the CozyStay WordPress theme to version 1.7.1 or later immediately
• Audit WordPress installations to identify all instances running vulnerable versions
• Review server logs for signs of exploitation attempts or successful compromise
• Consider temporarily disabling the CozyStay theme if immediate patching is not possible

Patch Information

LoftOcean has addressed this vulnerability in CozyStay version 1.7.1. Site administrators should update to this version or later through the WordPress theme update mechanism or by downloading the latest version from the official source. After updating, verify the theme version in the WordPress admin dashboard under Appearance > Themes.

Workarounds

• Deploy a Web Application Firewall (WAF) with rules to filter serialized PHP data in incoming requests
• Implement input validation at the server level to reject requests containing suspicious serialized object patterns
• Restrict access to the WordPress admin area and theme-related endpoints to trusted IP addresses
• Consider using security plugins that provide runtime protection against object injection attacks

# Verify CozyStay theme version
wp theme list --name=cozystay --fields=name,version,update

# Update CozyStay theme to latest version
wp theme update cozystay

# Check for signs of compromise in WordPress files
find /path/to/wordpress -name "*.php" -mtime -7 -type f