GLSA-202012-06 : Linux-PAM: Authentication bypass

critical Nessus Plugin ID 143493
New! Plugin Severity Now Using CVSS v3

The calculated severity for Plugins has been updated to use CVSS v3 by default. Plugins that do not have a CVSS v3 score will fall back to CVSS v2 for calculating severity. Severity display preferences can be toggled in the settings dropdown.

Synopsis

The remote Gentoo host is missing one or more security-related patches.

Description

The remote host is affected by the vulnerability described in GLSA-202012-06 (Linux-PAM: Authentication bypass)

A flaw was found in Linux-Pam in the way it handle empty passwords for non-existing users.
Impact :

A remote attacker, who only needs to know a non-existing username, could bypass security restrictions and authenticate as root user.
Workaround :

Ensure that root account is protected by a non-empty password.

Solution

All Linux-PAM users should upgrade to the latest version:
# emerge --sync # emerge --ask --oneshot --verbose '>=sys-libs/pam-1.5.1'

See Also

https://security.gentoo.org/glsa/202012-06

Plugin Details

Severity: Critical

ID: 143493

File Name: gentoo_GLSA-202012-06.nasl

Version: 1.3

Type: local

Published: 12/7/2020

Updated: 12/28/2020

Dependencies: ssh_get_info.nasl

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

Vector: AV:N/AC:L/Au:N/C:C/I:C/A:C

Temporal Vector: E:U/RL:OF/RC:C

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:gentoo:linux:pam, cpe:/o:gentoo:linux

Required KB Items: Host/local_checks_enabled, Host/Gentoo/release, Host/Gentoo/qpkg-list

Exploit Ease: No known exploits are available

Patch Publication Date: 12/7/2020

Vulnerability Publication Date: 12/18/2020

Reference Information

CVE: CVE-2020-27780

GLSA: 202012-06