zot is ancontainer image/artifact registry based on the Open Container Initiative Distribution Specification. From 1.3.0 to 2.1.14, zot’s dist-spec authorization middleware infers the required action for PUT /v2/{name}/manifests/{reference} as create by default, and only switches to update when the tag already exists and reference != "latest". As a result, when latest already exists, a user who is allowed to create (but not allowed to update) can still pass the authorization check for an overwrite attempt of latest. This vulnerability is fixed in 2.1.15.
zot is a production-ready vendor-neutral OCI image registry. The group data stored for users in the boltdb database (meta.db) is an append-list so group revocations/removals are ignored in the API. SetUserGroups is alled on login, but instead of replacing the group memberships, they are appended. This may be due to some conflict with the group definitions in the config file, but that wasn't obvious to me if it were the case. Any Zot configuration that relies on group-based authorization will not respect group remove/revocation by an IdP. This issue has been addressed in version 2.1.2. All users are advised to upgrade. There are no known workarounds for this vulnerability.