Ubuntu Security Notice 2935-2 – USN-2935-1 fixed vulnerabilities in PAM. The updates contained a packaging change that prevented upgrades in certain multiarch environments. This update fixes the problem. 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. 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. 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. Various other issues were also addressed.