Updated samba4 packages that fix one security issue, multiple bugs, and add various enhancements are now available for Red Hat Enterprise Linux 6.
The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) associated with each description below.
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.
The samba4 packages have been upgraded to upstream version 4.0.0, which provides a number of bug fixes and enhancements over the previous version. In particular, improved interoperability with Active Directory (AD) domains. SSSD now uses the libndr-krb5pac library to parse the Privilege Attribute Certificate (PAC) issued by an AD Key Distribution Center (KDC).
The Cross Realm Kerberos Trust functionality provided by Identity Management, which relies on the capabilities of the samba4 client library, is included as a Technology Preview. This functionality and server libraries, is included as a Technology Preview. This functionality uses the libndr-nbt library to prepare Connection-less Lightweight Directory Access Protocol (CLDAP) messages.
Additionally, various improvements have been made to the Local Security Authority (LSA) and Net Logon services to allow verification of trust from a Windows system. Because the Cross Realm Kerberos Trust functionality is considered a Technology Preview, selected samba4 components are considered to be a Technology Preview. For more information on which Samba packages are considered a Technology Preview, refer to Table 5.1, "Samba4 Package Support" in the Release Notes
A flaw was found in the Samba suite's Perl-based DCE/RPC IDL (PIDL) compiler, used to generate code to handle RPC calls. This could result in code generated by the PIDL compiler to not sufficiently protect against buffer overflows.
Prior to this update, if the Active Directory (AD) server was rebooted, Winbind sometimes failed to reconnect when requested by "wbinfo -n" or "wbinfo -s" commands. Consequently, looking up users using the wbinfo tool failed. This update applies upstream patches to fix this problem and now looking up a Security Identifier (SID) for a username, or a username for a given SID, works as expected after a domain controller is rebooted.
All users of samba4 are advised to upgrade to these updated packages, which fix these issues and add these enhancements. Warning: If you upgrade from Red Hat Enterprise Linux 6.3 to Red Hat Enterprise Linux 6.4 and you have Samba in use, you should make sure that you uninstall the package named "samba4" to avoid conflicts during the upgrade.