NextGEN Gallery version prior to 4.2.1 are vulnerable to authenticated SQL injection via the 'orderby' parameter on the REST API endpoints '/imagely/v1/galleries' and '/imagely/v1/albums'.

The root cause is an insufficient sanitization function ('cleancolumn()') in the data mapper layer that uses a character blacklist instead of a whitelist approach. This allows an authenticated attacker with the 'NextGEN Gallery overview' capability (assigned to the Administrator role by default) to inject arbitrary SQL into the 'ORDER BY' clause.

The Photo Gallery, Sliders, Proofing and Themes – NextGEN Gallery plugin for WordPress is vulnerable to Insecure Direct Object Reference in versions up to and including 4.2.0. This is due to insufficient object-level authorization in the image deletion REST flow where the permission callback for DELETE /imagely/v1/images/{id} only checks 'NextGEN Manage gallery' permissions and does not enforce gallery ownership or 'NextGEN Manage others gallery' permissions. This makes it possible for authenticated attackers, with Subscriber-level privileges and 'NextGEN Manage gallery' capability, to delete gallery images belonging to other users as well as their associated image files from disk when deleteImg is enabled (default).