Apache Storm Nimbus

Description getTopologyPageInfo merged the Nimbus daemon configuration with the topology's own configuration and returned the result without redaction in the topology_conf field of TopologyPageInfo. The Storm UI copied that value verbatim into the configuration field of GET /api/v1/topology/{id} and of the corresponding metrics endpoint. Where the cluster is configured with them, the merged map includes storm.zookeeper.auth.payload, which Storm's own documentation directs operators to keep in storm-cluster-auth.yaml under permissions that deny access from workers, together with the keystore and truststore passwords for the Thrift, Netty and ZooKeeper TLS configuration, and any plugin key whose name denotes a secret. getTopologyPageInfo is a topology read-only operation. Under SimpleACLAuthorizer a principal listed in topology.readonly.users or topology.readonly.groups could therefore read daemon credentials that the dedicated cluster configuration API, getNimbusConf, redacts and that is gated on nimbus.users instead. The sibling operations that exist to serve configuration were masked; the topology page, which merges in strictly more daemon state, was not. Mitigation Upgrade to 3.1.0, where credential-bearing values are masked before any configuration is served over the Nimbus API. Users who cannot upgrade immediately should remove any principal that is not trusted with cluster credentials from topology.readonly.users, topology.readonly.groups, topology.users and topology.groups, and should rotate the ZooKeeper authentication payload and any TLS keystore or truststore passwords that were reachable through the topology page. Credit Wanxin Yin (yaklang.io) reported this issue to the Apache Security Team.

Published: 2026-09-14T13:57:59.045Z
Updated: 2026-09-14T19:49:29.948Z

Description When ZooKeeper authentication is configured, Storm deliberately retains `storm.zookeeper.topology.auth.payload` in the topology configuration, because workers need it. Nimbus then served that configuration verbatim to any caller holding read-only topology permissions, so a user whose only grant was the ability to view a topology received its ZooKeeper credential. That credential is not read-only. The cluster state implementation uses write-capable ACLs for worker heartbeats, backpressure and error state, so a recipient can forge or remove that state for the topology concerned. It is not a write credential on assignments. The same advisory covers the submission client, which logged the generated payload at INFO on every submission that generated one, and the SASL handlers, which logged it at DEBUG. The credential therefore also reached any log aggregation or support bundle collected from the cluster. Mitigation Upgrade to 3.1.0, where the payload is removed from the configuration served to read-only callers and is no longer written to logs. Users who cannot upgrade immediately should rotate `storm.zookeeper.topology.auth.payload` for existing topologies, review retained logs and support bundles for the value, and restrict read-only topology permissions to trusted principals. Credit The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.

Published: 2026-09-14T14:10:15.326Z
Updated: 2026-09-14T19:50:34.074Z

Description Nimbus validated `topology.blobstore.map` against the calling subject at submission time only. The rebalance operation accepts configuration overrides and stripped a small set of keys from them, but never re-ran that validation, so a caller authorised to rebalance a topology could introduce a blobstore map entry naming a blob whose ACL does not grant them access. Supervisors localise whatever key the map names, placing the blob's contents into the topology's working directory. The same advisory covers `listBlobs`, which performed no authorization check and passed no subject, unlike the neighbouring `getBlobMeta` and `beginBlobDownload` operations. It therefore returned every key in the blobstore to any caller able to reach the Nimbus Thrift port, which provides the key names that make the above practical. On its own the disclosure is metadata only. Mitigation Upgrade to 3.1.0, where rebalance configuration overrides are validated exactly as submission-time configuration is, against the rebalancing caller, and where `listBlobs` applies the configured authorization. Users who cannot upgrade immediately should restrict rebalance rights to trusted principals, keeping in mind that membership of a topology's `topology.users` or `topology.groups` confers them. Credit The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.

Published: 2026-09-14T14:11:27.374Z
Updated: 2026-09-14T20:03:24.941Z

Description Nimbus accepted the `uploadedJarLocation` argument of `submitTopology` / `submitTopologyWithOpts` as a server-side path and opened it directly, without checking that it referred to a file the caller had actually uploaded. The intended flow is that a client first calls `beginFileUpload`, which returns a path inside the Nimbus inbox, and uploads the jar in chunks to that location; nothing bound submission to that flow, and the `uploaders` map populated by `beginFileUpload` was never consulted at submit time. An authenticated user with topology submission rights could therefore submit any path readable by the Nimbus daemon user as their topology jar. Nimbus copied the file into the topology's jar blob, and the blob ACL grants the submitting subject read access, so the contents could then be retrieved with the ordinary blob download RPCs. Candidate targets include the Nimbus Kerberos keytab, Thrift and UI TLS private keys, and `storm.yaml` with the ZooKeeper authentication payload. Possession of the Nimbus keytab turns an ordinary tenant into a cluster administrator. In a deployment configured as the documentation recommends, submission is available to every authenticated principal when `nimbus.users` is unset, so no elevated privilege is required. Mitigation Upgrade to 3.1.0, where the submitted location is canonicalised and must resolve inside the Nimbus inbox. Users who cannot upgrade immediately should restrict topology submission to trusted principals via `nimbus.users` or `nimbus.groups`, and should treat any file readable by the Nimbus daemon user as potentially exposed to submitters: rotate the Nimbus keytab and any TLS private keys or ZooKeeper credentials reachable from that account. Local mode is unaffected. Credit Independently reported to the Apache Storm PMC by n0mi1k, with a proof of concept. Also found by the ASF using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.

Published: 2026-09-14T14:04:16.954Z
Updated: 2026-09-14T19:53:45.290Z

Description A submitted topology carries two lists of blobstore keys, `dependency_jars` and `dependency_artifacts`, which the client fills in after uploading the corresponding blobs. Nimbus performed no validation of their contents on the submission path, yet acts on them in two places. During cleanup of a finished topology, Nimbus deletes the keys named in those lists, and the deletion is performed as the Nimbus subject, for which the blobstore short-circuits its ACL check. A submitter who listed a key belonging to another topology, such as its `-stormjar.jar`, could therefore cause that blob to be deleted when their own topology was cleaned up. Separately, on acquiring leadership a Nimbus compares the dependency keys of all active topologies against the blobstore contents and surrenders leadership if any is missing. A single key that does not exist, on a single active topology, therefore causes every Nimbus to acquire leadership, surrender it and requeue indefinitely, leaving the cluster without a leader and unable to schedule, clean up or accept submissions. Mitigation Upgrade to 3.1.0, where a submission is refused unless every entry in both lists is a dependency blob key and exists in the blobstore. Note that this validates new submissions only; a topology stored by an affected version with an invalid list is unaffected by the upgrade. An operator whose cluster is failing to retain a leader should inspect the Nimbus log for the dependency keys reported as missing and remove or resubmit the topology naming them. Users who cannot upgrade immediately should restrict topology submission to trusted principals. Credit This issue was discovered by rzo1 while investigating an unrelated blobstore defect.

Published: 2026-09-14T13:58:56.249Z
Updated: 2026-09-14T19:44:33.448Z