Ubuntu 15.10, 14.04 LTS PAM Security Advisory USN-2935-1 Moderate Threat

ubuntu

March 16, 2016

Several security issues were fixed in PAM.

Summary

Several security issues were fixed in PAM.

Software Description:

- pam: Pluggable Authentication Modules

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)

Topics Covered

security advisory moderate denial of service authentication ubuntu brute force pam

Update Instructions

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 15.10:
  libpam-modules                  1.1.8-3.1ubuntu3.1

Ubuntu 14.04 LTS:
  libpam-modules                  1.1.8-1ubuntu2.1

Ubuntu 12.04 LTS:
  libpam-modules                  1.1.3-7ubuntu2.1

In general, a standard system update will make all the necessary changes.