OpenBao AWS Plugin Vulnerable to Cross-Account IAM Role Impersonation in AWS Auth Method

### Impact This is a cross-account impersonation vulnerability in the `auth-aws` plugin. The vulnerability allows an IAM role from an untrusted AWS account to authenticate by impersonating a role with the **same name** in a trusted account, leading to unauthorized access. This impacts all users of the `auth-aws` plugin who operate in a multi-account AWS environment where IAM role names may not be unique across accounts. The core of the vulnerability is a flawed caching mechanism that fails to validate the AWS Account ID during authentication. While the use of wildcards in a `bound_iam_principal_arn configuration` significantly increases the attack surface, **wildcards are not a prerequisite for exploitation**. The vulnerability can be exploited with specific ARN bindings if a role name collision occurs. Successful exploitation can lead to unauthorized access to secrets, data exfiltration, and privilege escalation. Given that the only prerequisite is a duplicate role name, the severity is considered **high**. ### Patches This vulnerability has been patched in version **0.1.1** of the `auth-aws` plugin. Users are advised to upgrade to version **0.1.1** or later to remediate this vulnerability. ### Workarounds For users who are unable to upgrade to version **0.1.1** immediately, the most effective workaround is to **guarantee that IAM role names are unique across all AWS accounts** that could potentially interact with your OpenBao environment. This is the most critical mitigation step. **Primary Mitigation**: Audit your AWS organizations to identify and rename any duplicate IAM role names. Enforce a naming convention that includes account-specific identifiers to prevent future collisions. While removing wildcards from your `bound_iam_principal_arn` configuration is still recommended as a security best practice, it **will not** mitigate this vulnerability if duplicate role names exist. ### Credits This vulnerability was discovered and reported by [Pavlos Karakalidis](https://github.com/pkarakal/)

Source published

23 Oct 2025 16:01:27 UTC

Source modified

5 Nov 2025 19:57:32 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Publisher rating · HIGH