The owner_set function in smbcacls.c in smbcacls in Samba 4.0.x before 4.0.16 and 4.1.x before 4.1.6 removes an ACL during use of a --chown or --chgrp option, which allows remote attackers to bypass intended access restrictions in opportunistic circumstances by leveraging an unintended administrative change.
https://bugzilla.samba.org/show_bug.cgi?id=10327
http://www.securityfocus.com/bid/66232
http://www.samba.org/samba/security/CVE-2013-6442
http://www.samba.org/samba/history/samba-4.1.6.html
http://www.samba.org/samba/history/samba-4.0.16.html
http://lists.opensuse.org/opensuse-updates/2014-03/msg00062.html
http://lists.fedoraproject.org/pipermail/package-announce/2014-June/134717.html
http://lists.fedoraproject.org/pipermail/package-announce/2014-August/136864.html