Samba is an open-source implementation of the Server Message Block or Common Internet File System protocol, which allows PC-compatible machines to share files, printers, and other information. A flaw was found in the way Samba handled certain Local Security Authority Remote Procedure Calls . An authenticated user could use this flaw to issue an RPC call that would modify the privileges database on the Samba server, allowing them to steal the ownership of files and directories that are being shared by the Samba server, and create, delete, and modify user accounts, as well as other Samba server administration tasks. Red Hat would like to thank the Samba project for reporting this issue. Upstream acknowledges Ivano Cristofolini as the original reporter. Users of Samba are advised to upgrade to these updated packages, which contain a backported patch to resolve this issue. After installing this update, the smb service will be restarted automatically.