Dgraph: Zero Unauthenticated HTTP Admin removeNode Denial of Service

Dgraph is an open source distributed GraphQL database. Prior to 25.4.0, Dgraph Zero registers administrative HTTP routes on port 6080 without authentication when the administrative interface is enabled. The /removeNode route accepts attacker-controlled id and group values and passes them to Server.RemoveNode, where group 0 can trigger ProposePeerRemoval. A remote unauthenticated attacker who can reach the Zero HTTP port can read topology through /state, allocate identifiers through /assign, access the exposed /moveTablet administrative route, or remove membership through /removeNode, disrupting the Zero control plane and destabilizing Alpha nodes that depend on Zero. The route registration occurs in dgraph/cmd/zero/run.go, and the demonstrated membership-removal path reaches Server.RemoveNode and ProposePeerRemoval. This issue is fixed in version 25.4.0.