CVE-2023-6846 in File Manager Pro Plugin
Summary
by MITRE • 02/06/2024
The File Manager Pro plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 8.3.4 via the mk_check_filemanager_php_syntax AJAX function. This makes it possible for authenticated attackers, with subscriber access and above, to execute code on the server. Version 8.3.5 introduces a capability check that prevents users lower than admin from executing this function.
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Analysis
by VulDB Data Team • 10/18/2024
The File Manager Pro plugin for WordPress represents a critical security vulnerability that has affected versions up to and including 8.3.4, creating a significant risk for WordPress installations that rely on this plugin for file management operations. This vulnerability stems from an insufficient access control mechanism within the mk_check_filemanager_php_syntax AJAX function, which allows authenticated users with subscriber-level privileges or higher to bypass normal security restrictions. The flaw operates as an arbitrary file upload vulnerability, where malicious actors can upload potentially harmful files to the server and subsequently execute code remotely, fundamentally compromising the integrity and security of the affected WordPress environment.
The technical implementation of this vulnerability occurs through the AJAX endpoint that processes file syntax checking operations within the plugin's file manager functionality. When an authenticated user accesses this specific AJAX function, the plugin fails to properly validate user capabilities before allowing file upload operations. This oversight creates a direct pathway for privilege escalation, as users with minimal permissions can leverage the function to upload PHP files or other executable content to the server. The vulnerability specifically targets the mk_check_filemanager_php_syntax endpoint, which should only be accessible to administrators but remains accessible to subscribers and other lower-privileged user roles, effectively creating an unauthorized code execution vector.
The operational impact of this vulnerability extends far beyond simple file management capabilities, as it enables attackers to gain complete control over the compromised WordPress installation. Once an attacker successfully uploads malicious files through this vulnerability, they can execute arbitrary code on the server, potentially leading to data breaches, website defacement, or the establishment of persistent backdoors. This arbitrary file upload vulnerability directly maps to CWE-434, which describes the weakness of allowing untrusted data to be uploaded to a web server, and represents a critical security flaw that could be exploited by attackers to compromise entire web applications. The vulnerability's impact is particularly severe because it requires minimal privileges to exploit, making it accessible to users who would normally have limited access to system-level functions.
The remediation for this vulnerability was addressed in version 8.3.5 of the File Manager Pro plugin, which introduced a critical capability check that restricts access to the mk_check_filemanager_php_syntax function to administrator-level users only. This fix implements proper access control mechanisms that align with the principle of least privilege, ensuring that only users with appropriate administrative capabilities can access the file upload functionality. Organizations should immediately upgrade to version 8.3.5 or later to mitigate this vulnerability, while also implementing additional security measures such as monitoring for unauthorized file uploads, restricting user permissions where possible, and conducting regular security audits of installed plugins. The vulnerability's classification under ATT&CK technique T1505.003 highlights its potential for persistence and privilege escalation, making immediate remediation essential for maintaining secure WordPress environments.