CVE-2023-44981

A flaw was found in Apache ZooKeeper. Authorization bypass through user-controlled key is available iff SASL Quorum Peer authentication is enabled in ZooKeeper via quorum.auth.enableSasl=true configuration. A malicious user could bypass the authentication controller by using a non-existing instance part in SASL authentication ID (which is optional), therefore, the server would skip this check and as a result, join the cluster and propagate information with complete read and write access.

Mitigation

According to Apache's document: Ensure the ensemble election/quorum communication is protected by a firewall as this will mitigate the issue.