6 - RHSA-2017:1265

Problem Description:

An update for samba is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Client (v. 7) - noarch, x86_64 Red Hat Enterprise Linux Client Optional (v. 7) - noarch, x86_64 Red Hat Enterprise Linux ComputeNode (v. 7) - noarch, x86_64 Red Hat Enterprise Linux ComputeNode Optional (v. 7) - noarch, x86_64 Red Hat Enterprise Linux Server (v. 7) - aarch64, noarch, ppc64, ppc64le, s390x, x86_64 Red Hat Enterprise Linux Server Optional (v. 7) - aarch64, noarch, ppc64, ppc64le, s390x, x86_64 Red Hat Enterprise Linux Server Resilient Storage (v. 7) - x86_64 Red Hat Enterprise Linux Workstation (v. 7) - noarch, x86_64 Red Hat Enterprise Linux Workstation Optional (v. 7) - noarch, x86_64

3. Description:

Samba is an open-source implementation of the Server Message Block (SMB) protocol and the related Common Internet File System (CIFS) protocol, which allow PC-compatible machines to share files, printers, and various information.

Security Fix(es):

* It was found that Samba always requested forwardable tickets when using Kerberos authentication. A service to which Samba authenticated using Kerberos could subsequently use the ticket to impersonate Samba to other services or domain users. (CVE-2016-2125)

* A flaw was found in the way Samba handled PAC (Privilege Attribute Certificate) checksums. A remote, authenticated attacker could use this flaw to crash the winbindd process. (CVE-2016-2126)

* A race condition was found in samba server. A malicious samba client could use this flaw to access files and directories, in areas of the server file system not exported under the share definitions. (CVE-2017-2619)

Red Hat would like to thank the Samba project for reporting CVE-2017-2619. Upstream acknowledges Jann Horn (Google) as the original reporter of CVE-2017-2619.

4. Solution:

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing this update, the smb service will be restarted automatically.

5. Bugs fixed (https://bugzilla.redhat.com/):

1403114 - CVE-2016-2125 samba: Unconditional privilege delegation to Kerberos servers in trusted realms 1403115 - CVE-2016-2126 samba: Flaws in Kerberos PAC validation can trigger privilege elevation 1429472 - CVE-2017-2619 samba: symlink race permits opening files outside share directory