Skip to main content

Boteraser | Website and Server Security Solutions

🛡️ CVE-2025-5689 — authd

🟠 CVSS 8.5 — High ✅ No Known Exploit CWE-269 NVD
8.5
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

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

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](https://documentation.ubuntu.com/authd/latest/howto/install-authd/#install-authd).
  • An OAuth 2.0 application was registered in Microsoft Entra ID or Google IAM, and the respective authd broker was installed ([authd-msentraid](https://snapcraft.io/authd-msentraid) or [authd-google](https://snapcraft.io/authd-google)) and [configured](https://documentation.ubuntu.com/authd/latest/howto/configure-authd/#broker-configuration).
  • sshd was [configured to enable SSH](https://documentation.ubuntu.com/authd/latest/howto/login-ssh/) access with authd, i.e.:

```

UsePAM yes

KbdInteractiveAuthentication yes

```

  • The username is allowed by the ssh_allowed_suffixes option in the [broker configuriation](https://documentation.ubuntu.com/authd/latest/howto/login-ssh/#broker-configuration).
  • The user is allowed by the [allowed_users option in the broker configuration](https://documentation.ubuntu.com/authd/latest/howto/configure-authd/#configure-allowed-users).
  • 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).

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality high, integrity low, availability none.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: Low — an ordinary user account is enough.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Changed — a successful attack reaches components beyond the vulnerable one.
  • Confidentiality impact: High — total loss, or loss the attacker controls.
  • Integrity impact: Low — limited, and the attacker does not choose what is affected.
  • Availability impact: None.

Weakness class

CVE-2025-5689 is classified as CWE-269: Improper Privilege Management. Privileges are assigned, dropped or restored incorrectly, leaving an actor with more access than intended.

Affected software

CVE-2025-5689 is recorded against 2 packages.

  • authd (fixed in 0.5.4)
  • github.com/ubuntu/authd

Timeline and source

Published on 16 June 2025 and last revised on 17 June 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

github.com

Other advisories for this package

authd has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-269: Improper Privilege Management) in other software:

Details

Severity HIGH
CVSS Score 8.5
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N
CWE CWE-269
Public Exploit ✅ No
Source NVD
Published 2025-06-16
Updated 2026-08-20
Modified 2026-06-17

Affected Packages

Software From version Fixed in
authd — 0.5.4
github.com/ubuntu/authd — —

Similar Threats

Site Security Check

Is authd part of your stack?

CVE-2025-5689 is rated CVSS 8.5 High. BotEraser scans your installation against known CVE records and tells you whether this vulnerability applies to the versions you actually run.

Scan My Site Free →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

Browse related advisories

All advisoriesCVECVE 2025
✓