CVE-2016-4422

Publication date 6 May 2016

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

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.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
libpam-sshauth	17.04 zesty	Not affected
	16.10 yakkety	Not affected
	16.04 LTS xenial	Fixed 0.3.1-1ubuntu2
	15.10 wily	Fixed 0.3.1-1ubuntu0.15.10.1
	14.04 LTS trusty	Fixed 0.3.1-1deb8u1build0.14.04.1
	12.04 LTS precise	Ignored end of life

Notes

sbeattie

simplified fix in oss-security posting

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
libpam-sshauth	Upstream: https://bazaar.launchpad.net/~ltsp-upstream/ltsp/libpam-sshauth/revision/114

Severity score breakdown

CVSS version: CVSS v3.0

Base score 9.8 · Critical

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality impact	High
Integrity impact	High
Availability impact	High

Scores

Parameter	Value
Base score	9.8 · Critical
Exploitability score	-
Impact score	-

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H