The vulnerability arises because the streaming interceptor chain on the frontend gRPC server does not include authorization checks for the AdminService/StreamWorkflowReplicationMessages endpoint. While unary RPCs enforce authentication and authorization when ClaimMapper and Authorizer are configured, this streaming endpoint accepts requests without credentials. Since the endpoint shares the same port as WorkflowService and cannot be disabled independently, an attacker with network access could open the replication stream without authentication. However, data exfiltration is limited by the history service's validation of cluster IDs and peer membership, requiring the attacker to have knowledge of the cluster configuration and a properly configured replication target. Temporal Cloud services are not affected by this issue.

An attacker with network access to the frontend port could open the replication stream without authentication, potentially leading to data exfiltration. However, successful exploitation requires the attacker to know the cluster configuration and for the replication target to be correctly configured. The history service performs validation of cluster IDs and peer membership before returning replication data, which limits the scope of the impact. Temporal Cloud is not affected, so this vulnerability impacts only on-premises or self-hosted deployments of temporal version 1.24.0.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. There is no official fix or temporary workaround indicated in the available data. Since the vulnerable endpoint cannot be disabled independently and shares the port with WorkflowService, network-level controls restricting access to the frontend port may reduce exposure. Monitor vendor communications for updates on patches or official mitigations.