HCSEC-2023-08 - Nomad Job Submitter Privilege Escalation Using Workload Identity

Bulletin ID: HCSEC-2023-08
Affected Products / Versions: Nomad and Nomad Enterprise 1.5.0; fixed in 1.5.1.
Publication Date: March 13, 2022

A vulnerability was identified in Nomad and Nomad Enterprise (“Nomad”) such that a user with the submit-job ACL capability can submit a job that can escalate to management-level privileges. This vulnerability, CVE-2023-1299, was introduced in Nomad 1.5.0 and fixed in Nomad 1.5.1.

Nomad 1.4.0 introduced the concept of workload identity so that tasks can access variables without needing to access them through Nomad HTTP API with an ACL token.

In 1.5.0, the identity block was introduced, which exposes the workload identity token to the workload so it can access Nomad HTTP API via a unix domain socket without configuring mTLS.

During internal testing, we discovered it was possible to abuse the workload identity to elevate to management-level privilege if the workload identity did not have any attached ACL policies.

Customers should evaluate the risk associated with this issue and consider upgrading to Nomad 1.5.1 or newer. See Nomad’s Upgrading for general guidance on this process.

This issue was identified by the Nomad engineering team.

We deeply appreciate any effort to coordinate disclosure of security vulnerabilities. For information about security at HashiCorp and the reporting of security vulnerabilities, please see https://hashicorp.com/security.