Description

A vulnerability in the Chef Automate API gateway and identity validation path may allow an unauthenticated actor to gain elevated access to protected Chef Automate functionality under specific conditions.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "10.0",
  "pubDate": "2026-09-11T13:18:18.300Z",
  "pubdate": "2026-09-11T13:18:18.300Z",
  "executiveSummary": "This vulnerability involves an authentication bypass flaw within the Chef Automate API gateway and identity validation framework.\nThe vulnerability allows an unauthenticated, remote actor to circumvent established access controls and gain unauthorized, elevated access to sensitive system functionality.\nThe primary risk is the loss of confidentiality and integrity of the Chef Automate environment, as attackers may interact with privileged API endpoints without valid credentials.\nThe flaw stems from a defect in how the API gateway verifies identity claims during the request handling lifecycle, potentially permitting requests that should be rejected to reach protected internal services.\nNo specific user interaction is required for exploitation, and the attack surface is exposed via the standard network-accessible API gateway.\nThe impact includes full compromise of administrative operations depending on the scope of the affected endpoints reachable through the bypass.",
  "technicalDetails": "The root cause of this vulnerability lies in the improper implementation of request validation and authentication enforcement within the Chef Automate API gateway component. The gateway functions as a reverse proxy and identity provider integration point, responsible for intercepting incoming HTTP/S requests and verifying the integrity and validity of security tokens (such as Bearer tokens or mTLS client certificates) before forwarding requests to downstream internal services.\nThe vulnerability manifests when the API gateway fails to consistently enforce identity validation in specific code paths during the request routing process. Under specific architectural conditions—likely related to how the gateway evaluates header-based identity claims or path-based authorization rules—the system may incorrectly categorize a request as authorized or bypass the authentication handshake entirely.\nThe attack flow proceeds as follows: 1) The attacker initiates a crafted request targeted at sensitive or administrative API endpoints protected by the gateway. 2) The attacker manipulates request headers or payload structures in a manner that triggers the faulty logic in the identity validation module. 3) The API gateway, failing to validate the authentication context or incorrectly processing the security context, erroneously promotes the request to an authorized state. 4) The gateway proxies the request to the target internal microservice, which assumes the request has already been validated by the gateway's security layer. 5) The internal service executes the requested operation with elevated privileges, resulting in unauthorized data access or system configuration changes.\nThe vulnerable component is the primary API gateway service responsible for identity mediation. Because this component sits at the perimeter of the internal service mesh, an unauthenticated actor with network visibility can leverage this flaw to bypass the entire authentication layer. The behavior is particularly dangerous because the underlying microservices often rely on the 'Zero Trust' assumption that any incoming request from the gateway has been pre-authenticated and authorized according to global policy.\nPost-exploitation, an attacker may perform actions equivalent to those of an authenticated administrator, including modifying node configurations, altering compliance reports, or potentially pivoting into the underlying infrastructure managed by Chef Automate. The lack of robust 'Defense-in-Depth' validation at the individual service level exacerbates the impact of this gateway-level failure."
}