SB2024101077 - Incorrect User Management in authd

Description

This security bulletin contains information about 1 security vulnerability.

1) Incorrect User Management (CVE-ID: CVE-2024-9312)

The vulnerability allows a local privileged user to gain another user's privileges.

The vulnerability exists due to incorrect user management in the GenerateID method and user ID assignment logic when registering user names. A local privileged user can register a user name that yields a colliding UID to gain another user's privileges.

Exploitation requires the ability to register user names, and the issue can be triggered because user ID uniqueness is checked only against a local cache that may be inconsistent, purged, or missing inactive users.

Remediation

Install update from vendor's website.

References

• https://github.com/ubuntu/authd/security/advisories/GHSA-4gfw-wf7c-w6g2
• https://github.com/advisories/GHSA-4gfw-wf7c-w6g2