GHSA-g8qw-mgjx-rwjr

Source

https://github.com/advisories/GHSA-g8qw-mgjx-rwjr

Import Source

https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/06/GHSA-g8qw-mgjx-rwjr/GHSA-g8qw-mgjx-rwjr.json

JSON Data

https://api.test.osv.dev/v1/vulns/GHSA-g8qw-mgjx-rwjr

Aliases

Published

2025-06-16T16:01:10Z

Modified

2025-07-28T20:30:05.790813Z

Severity

6.4 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N CVSS Calculator

Summary

New authd users logging in via SSH are members of the root group

Details

Impact

When an authd user logs in via SSH for the first time (meaning they do not yet exist in the authd user database) and successfully authenticates via the configured broker, the user is considered a member of the root group in the context of that SSH session. This situation may allow the user to read and write files that are accessible by the root group, to which they should not have access. The user does not get root privileges or any capabilities beyond the access granted to the root group.

Preconditions under which this vulnerability affects a system * authd was installed via the PPA. * An OAuth 2.0 application was registered in Microsoft Entra ID or Google IAM, and the respective authd broker was installed (authd-msentraid or authd-google) and configured. * sshd was configured to enable SSH access with authd, i.e.:

UsePAM yes
KbdInteractiveAuthentication yes

* The username is allowed by the ssh_allowed_suffixes option in the broker configuriation. * The user is allowed by the <code>allowed_users</code> option in the broker configuration. * The user successfully authenticates via the authd broker (Entra ID or Google IAM). * The user did not log in locally before.

Patches

Fixed by https://github.com/ubuntu/authd/commit/619ce8e55953b970f1765ddaad565081538151ab

Workarounds

Configure the SSH server to not allow authenticating via authd, for example by setting UsePAM no or KbdInteractiveAuthentication no in the sshd_config (see https://documentation.ubuntu.com/authd/stable/howto/login-ssh/#ssh-configuration).

Database specific

{
    "nvd_published_at": "2025-06-16T12:15:19Z",
    "github_reviewed": true,
    "github_reviewed_at": "2025-06-16T16:01:10Z",
    "severity": "MODERATE",
    "cwe_ids": [
        "CWE-266",
        "CWE-269"
    ]
}

References

Affected packages

Go / github.com/ubuntu/authd

Package

Name: github.com/ubuntu/authd; View open source insights on deps.dev
Purl: pkg:golang/github.com/ubuntu/authd

Affected ranges

Type: SEMVER
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

0.5.4