CVE-2025-54742: WpEvently Object Injection Vulnerability

CVE-2025-54742 Overview

CVE-2025-54742 is a PHP Object Injection vulnerability in the WpEvently plugin (mage-eventpress) developed by magepeopleteam for WordPress. The flaw stems from deserialization of untrusted data [CWE-502] and affects all plugin versions up to and including 4.4.8. An authenticated attacker with low privileges can submit crafted serialized payloads that the plugin processes through unsafe deserialization. Successful exploitation can lead to arbitrary object instantiation, which often results in remote code execution, file manipulation, or data exfiltration depending on the available POP gadget chains in the WordPress environment.

Critical Impact
Authenticated attackers can trigger PHP Object Injection in WpEvently ≤ 4.4.8, potentially achieving code execution and full compromise of the WordPress site.

Affected Products

magepeopleteam WpEvently (mage-eventpress) plugin for WordPress
All versions from initial release through 4.4.8
WordPress sites running the plugin with authenticated user access enabled

Discovery Timeline

2025-08-28 - CVE-2025-54742 published to NVD
2026-04-23 - Last updated in NVD database

Technical Details for CVE-2025-54742

Vulnerability Analysis

The vulnerability resides in how the WpEvently plugin handles serialized PHP data. The plugin invokes unserialize() on input that originates from an untrusted source without performing prior validation or integrity checks. When PHP deserializes attacker-controlled data, it instantiates objects and triggers magic methods such as __wakeup(), __destruct(), or __toString(). In a WordPress context, this behavior can be chained with property-oriented programming (POP) gadgets from WordPress core or other installed plugins to achieve arbitrary file writes, SQL execution, or remote code execution. The attack requires authentication, but the privilege threshold is low, expanding the population of potential abusers on multi-user sites.

Root Cause

The root cause is the use of unsafe PHP deserialization on untrusted input within the mage-eventpress codebase. The plugin does not enforce allow-lists for permitted classes, nor does it use safer alternatives such as json_decode() or unserialize() with the allowed_classes option set to false. This omission allows arbitrary object graphs to be constructed during request processing.

Attack Vector

Exploitation requires network access to the WordPress site and a low-privileged authenticated account. The attacker submits a crafted serialized payload through a plugin endpoint that reaches the vulnerable unserialize() call. Because no user interaction is required and the attack traverses standard HTTP/HTTPS channels, automation is straightforward against exposed installations.

No verified proof-of-concept code is publicly available. Refer to the Patchstack Vulnerability Report for additional technical detail.

Detection Methods for CVE-2025-54742

Indicators of Compromise

HTTP POST requests to WpEvently endpoints containing serialized PHP strings beginning with O:, a:, or s: followed by length and class markers
Unexpected creation or modification of PHP files under wp-content/uploads/ or plugin directories
New or unfamiliar administrator accounts in the WordPress users table
Outbound network connections originating from the php-fpm or web server process to attacker-controlled infrastructure

Detection Strategies

Inspect web application firewall (WAF) and access logs for request parameters containing PHP serialized object patterns sent to plugin URLs
Monitor the mage-eventpress plugin directory for unexpected file changes or new PHP files using file integrity monitoring
Correlate authenticated user activity against unusual POST request volumes targeting event-related endpoints

Monitoring Recommendations

Enable verbose logging for WordPress plugin requests and forward logs to a centralized analytics platform
Alert on PHP error logs containing unserialize() warnings or unexpected class instantiation messages
Track WordPress user role changes and privilege escalations following plugin interactions

How to Mitigate CVE-2025-54742

Immediate Actions Required

Identify all WordPress installations running the WpEvently (mage-eventpress) plugin and confirm installed versions
Disable or remove the plugin on sites running version 4.4.8 or earlier until a patched release is applied
Restrict registration and lower-privileged account creation on affected sites to reduce the authenticated attack surface
Review existing user accounts for unauthorized additions or role escalations

Patch Information

At the time of NVD publication, the issue affects WpEvently versions through 4.4.8. Administrators should consult the Patchstack Vulnerability Report and the plugin vendor's release notes for the fixed version and apply the update across all WordPress instances.

Workarounds

Deploy a WAF rule that blocks request bodies and query parameters containing PHP serialized object signatures such as O: and a: followed by integer length tokens
Restrict access to WpEvently admin and AJAX endpoints to trusted IP ranges via web server configuration
Apply principle of least privilege by auditing and removing unnecessary subscriber, contributor, or author accounts

bash

# Example nginx rule to block serialized PHP object patterns in request bodies
location ~* /wp-content/plugins/mage-eventpress/ {
    if ($request_body ~* "(O|a):[0-9]+:\"") {
        return 403;
    }
}