USN-2935-3: PAM regression
17 March 2016
USN-2935-1 introduced a regression in PAM.
Releases
Packages
- pam - Pluggable Authentication Modules
Details
USN-2935-1 fixed vulnerabilities in PAM. The updates contained a packaging
change that prevented upgrades in certain multiarch environments. USN-2935-2
intended to fix the problem but was incomplete for Ubuntu 12.04 LTS. This
update fixes the problem in Ubuntu 12.04 LTS.
We apologize for the inconvenience.
Original advisory details:
It was discovered that the PAM pam_userdb module incorrectly used a
case-insensitive method when comparing hashed passwords. A local attacker
could possibly use this issue to make brute force attacks easier. This
issue only affected Ubuntu 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2013-7041)
Sebastian Krahmer discovered that the PAM pam_timestamp module incorrectly
performed filtering. A local attacker could use this issue to create
arbitrary files, or possibly bypass authentication. This issue only
affected Ubuntu 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2014-2583)
Sebastien Macke discovered that the PAM pam_unix module incorrectly handled
large passwords. A local attacker could possibly use this issue in certain
environments to enumerate usernames or cause a denial of service.
(CVE-2015-3238)
Update instructions
The problem can be corrected by updating your system to the following package versions:
Ubuntu 12.04
In general, a standard system update will make all the necessary changes.