CVE-2013-7041

Updated pam packages fix security vulnerabilities:

The pam_userdb module for Pam uses a case-insensitive method to compare hashed passwords, which makes it easier for attackers to guess the password via a brute force attack (CVE-2013-7041).

Multiple directory traversal vulnerabilities in pam_timestamp.c in the pam_timestamp module for Linux-PAM (aka pam) 1.1.8 allow local users to create aribitrary files or possibly bypass authentication via a .. (dot dot) in the PAM_RUSER value to the get_ruser function or (2) PAM_TTY value to the check_tty funtion, which is used by the format_timestamp_name function (CVE-2014-2583).

This update for pam fixes two security issues.

These security issues were fixed:

• CVE-2015-3238: pam_unix in conjunction with SELinux allowed for DoS attacks (bsc#934920).
• CVE-2013-7041: Compare password hashes case-sensitively (bsc#854480).

This non-security issue was fixed:

• bsc#962220: Don't fail when /var/log/btmp is corrupted

The pam_userdb module for Pam uses a case-insensitive method to compare hashed passwords, which makes it easier for attackers to guess the password via a brute force attack.

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)