Tina: Broken Access Control: arbitrary bucket-key write/delete in `next-tinacms-s3` (and sibling production media adapters)
The production media handler shipped by next-tinacms-s3 (createMediaHandler in packages/next-tinacms-s3/src/handlers.ts) accepts an attacker-chosen ?key= query parameter and returns an AWS-signed PutObject URL whose Key is that value, with no check that the key falls under the operator's configured mediaRoot. The same handler's DELETE branch reads objectKey = (req.query.media as string[])[1] and dispatches a DeleteObjectCommand for that exact key, again unbounded by mediaRoot. Any caller that passes the operator-supplied authorized() predicate …