Headline
GHSA-hh28-h22f-8357: OpenBao has a Timing Side-Channel in the Userpass Auth Method
Impact
When using OpenBao’s userpass auth method, user enumeration was possible due to timing difference between non-existent users and users with stored credentials. This is independent of whether the supplied credentials were valid for the given user.
Patches
OpenBao v2.3.2 will patch this issue.
Workarounds
Users may use another auth method or apply rate limiting quotas to limit the number of requests in a period of time: https://openbao.org/api-docs/system/rate-limit-quotas/
References
This issue was disclosed to HashiCorp and is the OpenBao equivalent of the following tickets:
- https://discuss.hashicorp.com/t/hcsec-2025-15-timing-side-channel-in-vault-s-userpass-auth-method/76034
- https://nvd.nist.gov/vuln/detail/CVE-2025-6011
Barring further information, this is also assumed to cover and remediate the following additional vulnerability:
- https://discuss.hashicorp.com/t/hcsec-2025-21-vault-user-enumeration-in-userpass-auth-method/76095
- https://nvd.nist.gov/vuln/detail/CVE-2025-6010
If this is not the case as further details emerge, a new CVE will be assigned for remediating that. Otherwise, no further CVE will be sought.
Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.