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: * A flaw was found in the way Samba initiated signed DCE/RPC connections. A man-in-the-middle attacker could use this flaw to downgrade the connection to not use signing and therefore impersonate the server. Red Hat would like to thank the Samba project for reporting this issue. Upstream acknowledges Stefan Metzmacher as the original reporter. Bug Fix: * Previously, the "net" command in some cases failed to join the client to Active Directory because the permissions setting prevented modification of the supported Kerberos encryption type LDAP attribute. With this update, Samba has been fixed to allow joining an AD domain as a user. In addition, Samba now uses the machine account credentials to set up the Kerberos encryption types within AD for the joined machine. As a result, using "net" to join a domain now works more reliably. * Previously, the idmap_hash module worked incorrectly when it was used together with other modules. As a consequence, user and group IDs were not mapped properly. A patch has been applied to skip already configured modules. Now, the hash module can be used as the default idmap configuration back end and IDs are resolved correctly