The LearnDash LMS plugin for WordPress is vulnerable to Unrestricted File Type Upload in versions up to and including 5.1.5. This is due to insufficient input validation in the 'learndash_fileupload_process' function, which iterates through an entire array and validates only the first file. This makes it possible for authenticated attackers, with subscriber-level access and above who are enrolled in a course with assignment uploads enabled, to upload arbitrary disallowed files, including PHP files, to the server's wp-content/uploads/learndash/assignments/ directory.
The uploaded files can only be used for Remote Code Execution if default server configurations have been changed to allow for execution.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v3.1