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CRE-2025-0045

NATS Authorization Failure DetectedMedium
Impact: 4/10
Mitigation: 4/10

CRE-2025-0045View on GitHub

Description

The NATS server has emitted an Authorization Violation log entry, meaning a client attempted to connect, publish, subscribe, or perform another operation for which it lacks permission. Intermittent violations often point to misconfiguration or start-up chaos. However, sustained or widespread violations can signal credential expiry or missing secrets.


Cause

* Client credentials (username/password, NKey, or JWT) are missing,

invalid, revoked, or expired.

* The client is connecting to the wrong account or lacks publish/subscribe

permissions for the subject it is using.

* Clock skew between client and server invalidates JWT `iat`/`exp` claims.

* TLS / mTLS mapping failure prevents the certificate from matching an

authorized user.

* Recent credential rotation not yet reflected in running deployments

(e.g., stale Kubernetes Secret or mis-configured CI pipeline).


Mitigation

  • Verify credentials – confirm the `.creds`, NKey, or JWT files in

the client deployment are correct and unexpired.

  • Check permissions – in the server configuration (`authorization {}`)

or the account JWT, ensure the user/account is allowed to perform the

attempted PUB/SUB/CONNECT operation.

  • Rotate or re-issue keys/JWTs if credentials are compromised or

expired, and update all clients.

  • Synchronize clocks on clients and servers via NTP to avoid JWT

time-skew errors.

  • Audit repeated failures – turn on verbose server logs temporarily

and review for malicious activity or configuration drift.


References