The Login as User plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 1.0.3. This is due to the handle_return_to_admin() function trusting a client-controlled cookie (oclaup_original_admin) to determine which user to authenticate as, without any server-side verification that the cookie value was legitimately set during an admin-initiated user switch. This makes it possible for authenticated attackers, with Subscriber-level access and above, to escalate their privileges to administrator by setting the oclaup_original_admin cookie to an administrator's user ID and triggering the "Return to Admin" functionality.

The Login as User plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 1.0.3. This is due to the handle_return_to_admin() function trusting a client-controlled cookie (oclaup_original_admin) to determine which user to authenticate as, without any server-side verification that the cookie value was legitimately set during an admin-initiated user switch. This makes it possible for authenticated attackers, with Subscriber-level access and above, to escalate their privileges to administrator by setting the oclaup_original_admin cookie to an administrator's user ID and triggering the "Return to Admin" functionality.