The Masteriyo LMS WordPress plugin before 3.4.1 does not verify ownership of, or restrict the type of, the records a user requests for download, allowing users with the instructor role to retrieve the full content and metadata of arbitrary posts, including other instructors' private and draft courses.

The Masteriyo LMS WordPress plugin before 3.4.1 does not prevent user-supplied values held as metadata from being deserialized when they are read back, allowing users with a minimal account to inject arbitrary PHP objects and, by way of a class shipped in a library bundled with the Masteriyo LMS WordPress plugin before 3.4.1, write and execute arbitrary code on the server. A weaker form of the same issue is reachable without an account and yields an arbitrary file write rather than code execution.