Description

UnixAuth lacks brute-force protection in Apache Ranger versions <= 2.8.0.  Note:  UnixAuth is NOT a recommended option for production deployments.  Users are recommended to upgrade to version 2.9.0, which fixes this issue.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.3",
  "pubDate": "2026-08-10T11:17:27.483Z",
  "pubdate": "2026-08-10T11:17:27.483Z",
  "executiveSummary": "This vulnerability involves a lack of brute-force protection within the UnixAuth authentication mechanism of Apache Ranger versions <= 2.8.0. The absence of rate limiting, account lockout policies, or progressive delays allows threat actors to execute automated, high-velocity credential guessing attacks against the authentication endpoint without impediment.\nThe primary impact of successful exploitation is unauthorized access to sensitive systems and data managed by Apache Ranger. Since UnixAuth is explicitly noted as a non-recommended option for production deployments, installations utilizing this legacy configuration face significantly elevated risk profiles.\nAttackers with network access to the vulnerable Apache Ranger instance can leverage automated scripting tools to submit continuous authentication requests iteratively. This capability enables adversaries to bypass standard authentication controls through sheer volume, potentially compromising valid user accounts via credential stuffing or brute-force dictionaries.\nExploitation requirements are minimal, primarily necessitating network connectivity to the authentication interface and valid or enumerated usernames. Remediation requires upgrading the affected software to version 2.9.0 or transitioning away from the vulnerable authentication backend entirely.",
  "technicalDetails": "The root cause of this vulnerability lies in the design of the UnixAuth module in Apache Ranger versions <= 2.8.0, which fails to implement defensive rate-limiting controls, request throttling, or account lockout mechanisms for authentication attempts. The vulnerable component is the UnixAuth authentication handler responsible for validating credentials against underlying Unix system user accounts.\nDuring an attack flow, an adversary initiates repeated authentication requests containing target usernames paired with automated permutations of passwords. Because the application processes each request sequentially without tracking failed attempt thresholds or enforcing temporary access blocks, the system remains entirely susceptible to programmatic brute-force enumeration.\nAuthentication requirements for initiating the attack are unauthenticated, as the flaw resides within the initial login validation phase itself. Privilege requirements are nonexistent for the attacker, who interacts directly with the network-exposed login interface. Network exposure depends on the deployment architecture of the Apache Ranger service, but typically involves accessibility over HTTP/HTTPS protocols utilized by administrative or client endpoints.\nPayload behavior during exploitation consists of repeated HTTP requests or protocol-specific authentication bindings containing randomized or dictionary-derived credential sets. Post-exploitation impact includes the successful acquisition of valid administrative or operational session tokens, allowing the adversary to pivot, escalate privileges within the perimeter of the Ranger policy manager, and compromise underlying secured data repositories."
}