CVE-2024-50408: Namaste! LMS Object Injection Vulnerability

CVE-2024-50408 Overview

CVE-2024-50408 is a PHP Object Injection vulnerability in the Namaste! LMS WordPress plugin developed by Kibokolabs. The flaw stems from insecure deserialization of untrusted data [CWE-502] and affects all plugin versions up to and including 2.6.3. An authenticated attacker with low privileges can inject crafted serialized PHP objects to trigger unintended application behavior. Successful exploitation can lead to remote code execution, data tampering, or full site compromise when a suitable gadget chain is available in the WordPress environment.

Critical Impact
An authenticated attacker with low-privilege access can execute arbitrary PHP objects, leading to complete confidentiality, integrity, and availability loss on the affected WordPress site.

Affected Products

Kibokolabs Namaste! LMS WordPress plugin versions up to and including 2.6.3
WordPress sites running the namaste-lms plugin with the vulnerable deserialization code path
Any hosting environment exposing the plugin to authenticated users

Discovery Timeline

2024-10-28 - CVE-2024-50408 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-50408

Vulnerability Analysis

The vulnerability is an Object Injection flaw caused by insecure PHP deserialization within the Namaste! LMS plugin. The plugin passes attacker-controllable input to PHP's unserialize() function without validating or restricting the object types produced. When PHP reconstructs an object from a serialized string, magic methods such as __wakeup(), __destruct(), and __toString() execute automatically. If a suitable gadget chain exists in WordPress core, another loaded plugin, or a theme, these magic methods can chain into file writes, arbitrary function calls, or command execution.

The attack requires only low-privilege authentication, which in a Namaste! LMS deployment typically corresponds to a student or subscriber role. Because the plugin exposes learning-management workflows to enrolled users, the attack surface is broad relative to admin-only bugs.

Root Cause

The root cause is unsafe use of unserialize() on data derived from HTTP request parameters, options, or user-controlled metadata handled by the namaste-lms plugin. The code path does not enforce an allow-list of classes via the allowed_classes option and does not use safer alternatives such as json_decode(). This behavior is classified as [CWE-502] Deserialization of Untrusted Data.

Attack Vector

Exploitation is network-based and requires an authenticated session with low privileges. The attacker submits a crafted serialized payload to a vulnerable plugin endpoint. PHP deserializes the payload, instantiating attacker-chosen classes and invoking their magic methods. When combined with a known gadget chain from WordPress or a co-installed plugin, this pattern yields arbitrary PHP execution, file manipulation, or database tampering within the WordPress process. For technical specifics, see the Patchstack WordPress Vulnerability Report.

Detection Methods for CVE-2024-50408

Indicators of Compromise

HTTP POST or GET parameters containing serialized PHP payloads that begin with markers such as O:, a:, or s: targeting namaste-lms endpoints.
Unexpected PHP files, webshells, or scheduled tasks created under wp-content/plugins/namaste-lms/ or wp-content/uploads/.
New or modified WordPress administrator accounts following requests from low-privilege user sessions.
Outbound network connections initiated by the PHP worker process to attacker-controlled infrastructure.

Detection Strategies

Inspect web server access logs for requests to Namaste! LMS endpoints containing serialized object patterns like O:8:"stdClass" or class names not used by the plugin.
Enable WordPress audit logging to correlate low-privilege user activity with file system or option table changes.
Deploy a Web Application Firewall (WAF) rule that flags serialized PHP payloads in request bodies destined for /wp-admin/admin-ajax.php and plugin routes.

Monitoring Recommendations

Monitor integrity of PHP files in wp-content/plugins/ and wp-content/themes/ using file integrity monitoring.
Alert on execution of shell utilities (sh, bash, curl, wget) spawned by the PHP-FPM or Apache process.
Track anomalous outbound connections from the web server to non-corporate destinations, particularly to newly registered domains.

How to Mitigate CVE-2024-50408

Immediate Actions Required

Update the Namaste! LMS plugin to a version later than 2.6.3 as soon as the vendor publishes a patched release.
Audit user accounts on the WordPress instance and remove untrusted low-privilege users that no longer require access.
Review web server and application logs for serialized payload patterns dating back to the plugin installation.
If a patched version is unavailable, deactivate and remove the namaste-lms plugin until a fix is released.

Patch Information

At the time of publication, the vulnerability affects all versions of Namaste! LMS up to and including 2.6.3. Administrators should consult the Patchstack advisory for the current patch status and upgrade to the fixed version once released by Kibokolabs.

Workarounds

Restrict access to the WordPress site to trusted authenticated users while a patch is unavailable.
Deploy a virtual patch via a WAF or Patchstack rule to block serialized PHP payloads targeting the plugin.
Disable the Namaste! LMS plugin on production sites that do not actively require its functionality.

bash

# Configuration example: WAF rule to block serialized PHP payloads targeting the plugin
# ModSecurity example rule
SecRule REQUEST_URI "@contains /wp-content/plugins/namaste-lms/" \
    "chain,phase:2,deny,status:403,id:1005040801,msg:'Blocked possible PHP object injection in Namaste! LMS'"
    SecRule ARGS|REQUEST_BODY "@rx O:[0-9]+:\"[a-zA-Z_\\\\]+\":[0-9]+:\{" "t:none"