What is CVE-2016-4422?

CVE-2016-4422 is a critical-severity vulnerability in Libpam-Sshauth Project, classified under Improper Authentication. CVSS score: 9.8/10. Published 2016-05-06.

How severe is CVE-2016-4422?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Auth bypass in Libpam-Sshauth Project

CVE-2016-4422

The pam_sm_authenticate function in pam_sshauth.c in libpam-sshauth might allow context-dependent attackers to bypass authentication or gain privileges via a system user account.

Vulnerability class: Broken Authentication

Published 2016-05-06 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.018 (77.7th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 78th percentile — 77.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.018 · newest: 0.018 · change: 0.000

Affected products

Libpam-Sshauth Project
Debian Linux — versions 8.0

Weakness classification (CWE)

CWE-287 — Improper Authentication

References

www.debian.org/security/2016/dsa-3567 (vendor-advisory, Third Party Advisory)
bazaar.launchpad.net/~ltsp-upstream/ltsp/libpam-sshauth/revision/114 (Broken Link)

Frequently asked questions

What is CVE-2016-4422?: CVE-2016-4422 is a critical-severity vulnerability in Libpam-Sshauth Project, classified under Improper Authentication. CVSS score: 9.8/10. Published 2016-05-06.
How severe is CVE-2016-4422?: Critical severity. CVSS v3 base score is 9.8 out of 10.