Samba version 4.0.0 up to 4.5.2 is vulnerable to privilege elevation due to incorrect handling of the PAC (Privilege Attribute Certificate) checksum. A remote, authenticated, attacker can cause the winbindd process to crash using a legitimate Kerberos ticket. A local service with access to the winbindd privileged pipe can cause winbindd to cache elevated access permissions.
https://www.samba.org/samba/security/CVE-2016-2126.html
https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA43730
https://access.redhat.com/errata/RHSA-2017:1265
http://www.securitytracker.com/id/1037495
http://www.securityfocus.com/bid/94994
http://rhn.redhat.com/errata/RHSA-2017-0744.html
http://rhn.redhat.com/errata/RHSA-2017-0662.html