CVE-2025-5689 Improper Permission Management in SSH Session Handling
First-time SSH logins via authd incorrectly assign root group permissions, allowing unauthorized privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-5689?
CVE-2025-5689 is a high-severity vulnerability in Canonical authd, published on 16 Jun 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A flaw was found in the temporary user record that authd uses in the pre-auth NSS. As a result, a user login for the first time will be considered to be part of the root group in the context of that SSH session.
Weakness: CWE-269
Which versions are affected by CVE-2025-5689?
3 open source packages ship an affected version, including github.com/ubuntu/authd. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/ubuntu/authd Go | All versions | 0.5.4 |
github.com/ubuntu/authd Go | All versions | 0.5.4 |
github.com/ubuntu/authd Go | All versions | 0.5.4 |
Products include Canonical Authd.
How do I fix CVE-2025-5689?
Upgrade github.com/ubuntu/authd to 0.5.4 or later.
Is CVE-2025-5689 being exploited?
There is no known exploitation of CVE-2025-5689 in the wild and no public exploit code.
Other vulnerabilities in Canonical authd
Sources
Also known as GHSA-g8qw-mgjx-rwjr, GO-2025-3762.