Samba is an open-source implementation of the Server Message Block (SMB) or Common Internet File System (CIFS) protocol, which allows PC-compatible machines to share files, printers, and other information.
A heap-based buffer overflow flaw was found in the DCE-RPC client code in Samba. A specially crafted DCE-RPC packet could cause various Samba programs to crash or, possibly, execute arbitrary code when parsed. A malicious or compromised Active Directory Domain Controller could use this flaw to compromise the winbindd daemon running with root privileges. (CVE-2013-4408)
A flaw was found in the way Samba performed ACL checks on alternate file and directory data streams. An attacker able to access a CIFS share with alternate stream support enabled could access alternate data streams regardless of the underlying file or directory ACL permissions. (CVE-2013-4475)
Red Hat would like to thank the Samba project for reporting CVE-2013-4408. Upstream acknowledges Stefan Metzmacher and Michael Adam of SerNet as the original reporters of this issue.
All users of Samba are advised to upgrade to these updated packages, which contain backported patches to correct these issues. After installing this update, the smb service will be restarted automatically.