Package Instance

Information disclosure
ZooKeeper's `getACL()` command does not check any permission when retrieves the ACLs of the requested node and returns all information contained in the ACL Id field as plaintext string. `DigestAuthenticationProvider` overloads the Id field with the hash value that is used for user authentication. As a consequence, if Digest Authentication is in use, the unsalted hash value will be disclosed by `getACL()` request for unauthenticated or unprivileged users.

Missing Authorization
No authentication/authorization is enforced when a server attempts to join a quorum in Apache ZooKeeper. As a result an arbitrary end point could join the cluster and begin propagating counterfeit changes to the leader.

Authorization Bypass Through User-Controlled Key vulnerability in Apache ZooKeeper. If SASL Quorum Peer authentication is enabled in ZooKeeper (quorum.auth.enableSasl=true), the authorization is done by verifying that the instance part in SASL authentication ID is listed in zoo.cfg server list. The instance part in SASL auth ID is optional and if it's missing, like 'eve@EXAMPLE.COM', the authorization check will be skipped. As a result an arbitrary endpoint could join the cluster and begin propagating counterfeit changes to the leader, essentially giving it complete read-write access to the data tree. Quorum Peer authentication is not enabled by default.

Users are recommended to upgrade to version 3.9.1, 3.8.3, 3.7.2, which fixes the issue.

Alternately ensure the ensemble election/quorum communication is protected by a firewall as this will mitigate the issue.

See the documentation for more details on correct cluster administration.

Missing Authentication for Critical Function
Two `wchp` and `wchc` commands are CPU intensive and could cause spike of CPU utilization on Apache ZooKeeper server if abused, which leads to the server unable to serve legitimate client requests.