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.

zot is an OCI image registry. Prior to 2.1.0, the cache driver `GetBlob()` allows read access to any blob without access control check. If a Zot `accessControl` policy allows users read access to some repositories but restricts read access to other repositories and `dedupe` is enabled (it is enabled by default), then an attacker who knows the name of an image and the digest of a blob (that they do not have read access to), they may maliciously read it via a second repository they do have read access to. This attack is possible because [`ImageStore.CheckBlob()` calls `checkCacheBlob()`](https://github.com/project-zot/zot/blob/v2.1.0-rc2/pkg/storage/imagestore/imagestore.go#L1158-L1159) to find the blob a global cache by searching for the digest. If it is found, it is copied to the user requested repository with `copyBlob()`. The attack may be mitigated by configuring "dedupe": false in the "storage" settings. The vulnerability is fixed in 2.1.0.