Subject: missing access controls for JS API in multi-tenancy

NATS-advisory-ID: 2025-01
Aliases: CVE-2025-30215, GHSA-fhg8-qxh5-7q3w
Date: 2025-04-08
Fixed-In: nats-server 2.11.1, 2.10.27

Background:

NATS.io is a high performance open source pub-sub distributed communication
technology, built for the cloud, on-premise, IoT, and edge computing.

The NATS account system provides for multi-tenancy and isolation.
JetStream provides for persistent storage of messages and at-least-once
guarantees.


Problem Description:

The management of JetStream assets happens with messages in the `$JS.`
subject namespace in the system account; this is partially exposed into
regular accounts to allow account holders to manage their assets.

Some of the JS API requests were missing access controls, allowing any
user with JS management permissions in any account to perform certain
administrative actions on any JS asset in any other account.
At least one of the unprotected APIs allows for data destruction.
None of the affected APIs allow disclosing stream contents.


Affected versions:

NATS Server:
 * Version 2 from v2.2.0 onwards, prior to v2.11.1 or v2.10.27


Workarounds:

None


Solution:

Upgrade the NATS server to a fixed version.


Credits:

This problem was reported by Thomas Morgan on 2025-03-05.


References:

 * This document is canonically:
   <https://advisories.nats.io/CVE/secnote-2025-01.txt>
 * GHSA advisory:
   <https://github.com/nats-io/nats-server/security/advisories/GHSA-fhg8-qxh5-7q3w>
 * MITRE CVE entry:
   <https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-30215>