The InfiniteWP Client plugin before 220.127.116.11 for WordPress has a missing authorization check in iwp_mmb_set_request in init.php. Any attacker who knows the username of an administrator can log in.
CWE-862 - Missing Authorization
The missing authorization vulnerability occurs when a software program allows users to access privileged parts of the program without verifying the user credentials. Impact of such a vulnerability depends on the resources employed by the software, ranging from account takeover to sensitive information exposure, denial of service, and complete system takeover.