Authd allows attacker-controlled usernames to yield controllable UIDs

published 2024-10-10 2 y ago modified 2026-06-17 4 mo ago also GHSA-4gfw-wf7c-w6g2 , GO-2024-3188 , EUVD-2024-2934

cvss: 7.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 20%
public exploits: 0; none known

Authd, through version 0.3.6, did not sufficiently randomize user IDs to prevent collisions. A local attacker who can register user names could spoof another user's ID and gain their privileges.

Patch / fix

fixed in 3 distros 2

go github.com/ubuntu/authd 0.3.6
Canonical Ltd. Authd 0.3.6
ubuntu authd 0.3.6

suse opensuse

govulncheck-vulndb SLE Module for Package Hub 15 SP6, openSUSE Leap 15.6 0.0.20250207T224745-150000.1.32.1
govulncheck-vulndb SLE Module for Package Hub 15 SP6, SLE Module for Package Hub 15 SP5, openSUSE Leap 15.6 +1 more 0.0.20241030T212825-150000.1.9.1

suse advisories SUSE-SU-2025:0429-1 SUSE-SU-2024:3911-1

govulncheck-vulndb Package Hub 12 0.0.20241104T154416-5.1
govulncheck-vulndb openSUSE Tumbleweed 0.0.20241030T212825-1.1

opensuse advisories openSUSE-SU-2024:0350-1 openSUSE-SU-2024:14447-1

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 2 y ago (2024-10-10)

Exploit prediction

0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/ubuntu/authd/security/advisories/GHSA-4gfw-wf7c-w6g2 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.5	CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
NVD	3.1	6.4	CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
GitHub	3.1	7.5	CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H

Affected packages

ecosystem	package	affected	fixed in
go	github.com/ubuntu/authd	<=0.0.0-20230706090440-d8cb2d561419 <0.3.6	0.3.6

Affected products

Canonical Ltd. Authd
ubuntu authd

Classification

Weakness

CWE-286 Incorrect User Management
CWE-335 Incorrect Usage of Seeds in Pseudo-Random Number Generator (PRNG)

References

github.com /ubuntu/authd/security/advisories/GHSA-4gfw-wf7c-w6g2
issue-tracking, web, exploit, mitigation, vendor-advisory, advisory
cve.org /CVERecord?id=CVE-2024-9312
issue-tracking, web, third-party-advisory
nvd.nist.gov /vuln/detail/CVE-2024-9312
advisory
github.com /ubuntu/authd
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary