ArchLinuxASA-202012-13[ASA-202012-13] pam: authentication bypass
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:L/Au:N/C:C/I:C/A:C
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
Percentile
55.6%
Arch Linux Security Advisory ASA-202012-13
Severity: High
Date : 2020-12-09
CVE-ID : CVE-2020-27780
Package : pam
Type : authentication bypass
Remote : No
Link : https://security.archlinux.org/AVG-1297
Summary
The package pam before version 1.5.0-2 is vulnerable to authentication
bypass.
Resolution
Upgrade to 1.5.0-2.
pacman -Syu “pam>=1.5.0-2”
The problem has been fixed upstream but no release is available yet.
Workaround
The issue can be mitigated by setting a non-empty password for the root
user.
Description
An authentication bypass issue was found in pam 1.5.0. Nonexistent
users could authenticate if the root password was empty.
Impact
In some unusual configurations, a remote user might be able to bypass
authentication.
References
https://github.com/linux-pam/linux-pam/blob/5b7ba35ebfd280c931933fedbf98cb7f4a8846f2/NEWS#L4-L5
https://github.com/linux-pam/linux-pam/pull/300
https://github.com/linux-pam/linux-pam/commit/30fdfb90d9864bcc254a62760aaa149d373fd4eb
https://security.archlinux.org/CVE-2020-27780
Related
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:L/Au:N/C:C/I:C/A:C
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
Percentile
55.6%