seunshare in policycoreutils 2.2.5 is owned by root with 4755 permissions, and executes programs in a way that changes the relationship between the setuid system call and the getresuid saved set-user-ID value, which makes it easier for local users to gain privileges by leveraging a program that mistakenly expected that it could permanently drop privileges.
http://www.securityfocus.com/bid/67341
http://www.oracle.com/technetwork/topics/security/linuxbulletinjan2016-2867209.html
http://www.mandriva.com/security/advisories?name=MDVSA-2015:156
http://secunia.com/advisories/59007
http://rhn.redhat.com/errata/RHSA-2015-0864.html
http://openwall.com/lists/oss-security/2014/05/08/1
http://openwall.com/lists/oss-security/2014/04/30/4
http://openwall.com/lists/oss-security/2014/04/29/7
http://lists.opensuse.org/opensuse-updates/2014-06/msg00008.html