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 ACLs on symbolic links. An authenticated user could use this flaw to gain access to an arbitrary file or directory by overwriting its ACL. Red Hat would like to thank the Samba project for reporting this issue. Upstream acknowledges Jeremy Allison and the Samba team as the original reporters. All samba users are advised to upgrade to these updated packages, which contain a backported patch to correct this issue. After installing this update, the smb service will be restarted automatically.