Samba is an open-source implementation of the Server Message Block protocol and the related Common Internet File System protocol, which allow PC-compatible machines to share files, printers, and various information. Security Fix: * It was found that Samba always requested forwardable tickets when using Kerberos authentication. A service to which Samba authenticated using Kerberos could subsequently use the ticket to impersonate Samba to other services or domain users. * A flaw was found in the way Samba handled PAC checksums. A remote, authenticated attacker could use this flaw to crash the winbindd process. * A race condition was found in samba server. A malicious samba client could use this flaw to access files and directories, in areas of the server file system not exported under the share definitions. Red Hat would like to thank the Samba project for reporting CVE-2017-2619. Upstream acknowledges Jann Horn as the original reporter of CVE-2017-2619.