high CVSS 7.5

CVE-2024-1895·PHP vulnerability

The Event Monster – Event Management, Tickets Booking, Upcoming Event plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 1.3.9 via deserialization via shortcode of untrusted input from a custom meta value. This makes it possible for authenticated attackers, with contributor access and above, to inject a PHP Object. No POP chain is present in the vulnerable plugin. If a POP chain is present via an additional plugin or theme installed on the target system, it could allow the attacker to delete arbitrary files, retrieve sensitive data, or execute code.

Severity
high
Software
PHP
Fixed in
1.4.0
Published
2024-04-30

Affected versions

Until: 1.4.0

Fixed in: 1.4.0

How to fix this CVE

Update the Event Monster plugin to version 1.4.0 or later to patch the PHP Object Injection vulnerability in the shortcode deserialization logic. If you are running PHP directly, ensure your system PHP packages are also fully updated. While the vulnerability requires authenticated access with contributor-level permissions, it can escalate to arbitrary file deletion or code execution if other vulnerable plugins or themes provide a suitable gadget chain on your system.

sudo dnf update php

Defensia detects this vulnerability

WAF mitigation (if patching is not yet possible)

Add this rule to your WAF to block exploitation attempts while you schedule the patch. 

Implement input validation on shortcode parameters to block serialized PHP objects (strings containing 'O:' or 'C:' followed by digit and colon patterns). Example pattern: ^O:[0-9]+:".*"|^C:[0-9]+:".*" — block these before they reach WordPress processing.

How to check if you are affected

  1. Step 1: Check installed PHP version with: php -v
  2. Step 2: Verify Event Monster plugin version by navigating to WordPress Plugins page or checking /wp-content/plugins/event-monster/event-monster.php for the Version header
  3. Step 3: Search WordPress debug logs and system PHP error logs for unserialize() warnings or notices related to shortcode processing: grep -r 'unserialize' /var/log/php* /var/www/html/wp-content/debug.log 2>/dev/null
  4. Step 4: Confirm the patch by verifying Event Monster is at version 1.4.0+ and checking the plugin changelog in the repository

FAQ

What is CVE-2024-1895?

CVE-2024-1895 is a PHP Object Injection vulnerability in the Event Monster WordPress plugin that occurs when shortcode attributes containing untrusted data are unserialized without validation, potentially allowing authenticated attackers to inject malicious objects.

Is CVE-2024-1895 being actively exploited?

No, CVE-2024-1895 is not listed on the CISA Known Exploited Vulnerabilities catalog and no public exploits are currently available.

What versions of PHP are affected by CVE-2024-1895?

The Event Monster plugin versions up to and including 1.3.9 are vulnerable; version 1.4.0 and later contain the fix. The vulnerability is inherent to the plugin code, not specific PHP versions, though PHP 7.0+ is typically affected.

How do I check if my server is vulnerable to CVE-2024-1895?

Run 'grep -r "Version:" /wp-content/plugins/event-monster/event-monster.php' to retrieve your Event Monster version; if it is 1.3.9 or earlier, your installation is vulnerable.

Does Defensia detect CVE-2024-1895?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If PHP is installed on a monitored server, CVE-2024-1895 will appear in your dashboard with remediation steps.

Related PHP CVEs

CVE-2026-39337CVSS 10ChurchCRM is an open-source church management system. Prior to 7.1.0, critical pre-authentication remote code execution vulnerability in ChurchCRM's setup wizard allows unauthenticated attackers to inject arbitrary PHP code during the initial installation process, leading to complete server compromise. The "$dbPassword" variable is not sanitized. This vulnerability exists due to an incomplete fix for CVE-2025-62521. This vulnerability is fixed in 7.1.0.
CVE-2024-5932CVSS 10The GiveWP – Donation Plugin and Fundraising Platform plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 3.14.1 via deserialization of untrusted input from the 'give_title' parameter. This makes it possible for unauthenticated attackers to inject a PHP Object. The additional presence of a POP chain allows attackers to execute code remotely, and to delete arbitrary files.
CVE-2026-28289CVSS 10FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. A patch bypass vulnerability for CVE-2026-27636 in FreeScout 1.8.206 and earlier allows any authenticated user with file upload permissions to achieve Remote Code Execution (RCE) on the server by uploading a malicious .htaccess file using a zero-width space character prefix to bypass the security check. The vulnerability exists in the sanitizeUploadedFileName() function in app/Http/Helper.php. The function contains a Time-of-Check to Time-of-Use (TOCTOU) flaw where the dot-prefix check occurs before sanitization removes invisible characters. This vulnerability is fixed in 1.8.207.
CVE-2025-62521CVSS 10ChurchCRM is an open-source church management system. Prior to version 5.21.0, a pre-authentication remote code execution vulnerability in ChurchCRM's setup wizard allows unauthenticated attackers to inject arbitrary PHP code during the initial installation process, leading to complete server compromise. The vulnerability exists in `setup/routes/setup.php` where user input from the setup form is directly concatenated into a PHP configuration template without any validation or sanitization. Any parameter in the setup form can be used to inject PHP code that gets written to `Include/Config.php`, which is then executed on every page load. This is more severe than typical authenticated RCE vulnerabilities because it requires no credentials and affects the installation process that administrators must complete. Version 5.21.0 patches the issue.
CVE-2025-47916CVSS 10Invision Community 5.0.0 before 5.0.7 allows remote code execution via crafted template strings to themeeditor.php. The issue lies within the themeeditor controller (file: /applications/core/modules/front/system/themeeditor.php), where a protected method named customCss can be invoked by unauthenticated users. This method passes the value of the content parameter to the Theme::makeProcessFunction() method; hence it is evaluated by the template engine. Accordingly, this can be exploited by unauthenticated attackers to inject and execute arbitrary PHP code by providing crafted template strings.

References

Track CVEs across your fleet automatically

Defensia scans your Linux servers and tells you exactly which ones are running vulnerable versions — including CVE-2024-1895. Free for 1 server.

Get started free