JoomSport < 5.1.8 - Unauthenticated PHP Object Injection

The joomsport_md_load AJAX action of the plugin, registered for both unauthenticated and unauthenticated users, unserialised user input from the shattr POST parameter, leading to a PHP Object Injection issue. Even though the plugin does not have a suitable gadget chain to exploit this, other installed plugins could, which might lead to more severe issues such as RCE

POST /wp-admin/admin-ajax.php
[...]

action=joomsport_md_load&mdId=1&shattr=Tzo0OiJURVNUIjowOnt9