Couchbase Server 4.0.0, 4.1.0, 4.1.1, 4.5.0, 4.5.1, 4.6.0 through 4.6.5, 5.0.0, 5.1.1, 5.5.0 and 5.5.1 have Insecure Permissions for the projector and indexer REST endpoints (they allow unauthenticated access).The /settings REST endpoint exposed by the projector process is an endpoint that administrators can use for various tasks such as updating configuration and collecting performance profiles. The endpoint was unauthenticated and has been updated to only allow authenticated users to access these administrative APIs.

In Couchbase Server 5.1.1, the cookie used for intra-node communication was not generated securely. Couchbase Server uses erlang:now() to seed the PRNG which results in a small search space for potential random seeds that could then be used to brute force the cookie and execute code against a remote system. This has been fixed in version 6.0.0.