The WP Directory Kit WordPress plugin before 1.5.7 does not sanitise and escape a parameter before using it in a SQL statement, allowing administrators to perform SQL injection attacks. On a multisite installation this lets an administrator of a single site read data belonging to the entire network, which they are not otherwise able to reach.
https://wpscan.com/vulnerability/e064c261-bc7b-4605-8da7-c7036fc396fc/