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 arbitrary files or possibly bypass authentication via a โฆ (dot dot) in the (1) PAM_RUSER value to the get_ruser function or (2) PAM_TTY value to the check_tty function, which is used by the format_timestamp_name function.
secunia.com/advisories/57317
www.openwall.com/lists/oss-security/2014/03/24/5
www.openwall.com/lists/oss-security/2014/03/26/10
www.openwall.com/lists/oss-security/2014/03/31/6
www.securityfocus.com/bid/66493
www.ubuntu.com/usn/USN-2935-1
www.ubuntu.com/usn/USN-2935-2
www.ubuntu.com/usn/USN-2935-3
git.fedorahosted.org/cgit/linux-pam.git/commit/?id=Linux-PAM-1_1_8-32-g9dcead8
security.gentoo.org/glsa/201605-05