==========================================================================
Ubuntu Security Notice USN-2855-1
January 05, 2016

samba vulnerabilities
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 15.10
- Ubuntu 15.04
- Ubuntu 14.04 LTS
- Ubuntu 12.04 LTS

Summary:

Several security issues were fixed in Samba.

Software Description:
- samba: SMB/CIFS file, print, and login server for Unix

Details:

Thilo Uttendorfer discovered that the Samba LDAP server incorrectly handled
certain packets. A remote attacker could use this issue to cause the LDAP
server to stop responding, resulting in a denial of service. This issue
only affected Ubuntu 14.04 LTS, Ubuntu 15.04 and Ubuntu 15.10.
(CVE-2015-3223)

Jan Kasprzak discovered that Samba incorrectly handled certain symlinks. A
remote attacker could use this issue to access files outside the exported
share path. (CVE-2015-5252)

Stefan Metzmacher discovered that Samba did not enforce signing when
creating encrypted connections. If a remote attacker were able to perform a
man-in-the-middle attack, this flaw could be exploited to view sensitive
information. (CVE-2015-5296)

It was discovered that Samba incorrectly performed access control when
using the VFS shadow_copy2 module. A remote attacker could use this issue
to access snapshots, contrary to intended permissions. (CVE-2015-5299)

Douglas Bagnall discovered that Samba incorrectly handled certain string
lengths. A remote attacker could use this issue to possibly access
sensitive information. (CVE-2015-5330)

It was discovered that the Samba LDAP server incorrectly handled certain
packets. A remote attacker could use this issue to cause the LDAP server to
stop responding, resulting in a denial of service. This issue only affected
Ubuntu 14.04 LTS, Ubuntu 15.04 and Ubuntu 15.10. (CVE-2015-7540)

Andrew Bartlett discovered that Samba incorrectly checked administrative
privileges during creation of machine accounts. A remote attacker could
possibly use this issue to bypass intended access restrictions in certain
environments. This issue only affected Ubuntu 14.04 LTS, Ubuntu 15.04 and
Ubuntu 15.10. (CVE-2015-8467)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 15.10:
  samba                           2:4.1.17+dfsg-4ubuntu3.1

Ubuntu 15.04:
  samba                           2:4.1.13+dfsg-4ubuntu3.1

Ubuntu 14.04 LTS:
  samba                           2:4.1.6+dfsg-1ubuntu2.14.04.11

Ubuntu 12.04 LTS:
  samba                           2:3.6.3-2ubuntu2.13

In general, a standard system update will make all the necessary changes.

References:
  http://www.ubuntu.com/usn/usn-2855-1
  CVE-2015-3223, CVE-2015-5252, CVE-2015-5296, CVE-2015-5299,
  CVE-2015-5330, CVE-2015-7540, CVE-2015-8467

Package Information:
  https://launchpad.net/ubuntu/+source/samba/2:4.1.17+dfsg-4ubuntu3.1
  https://launchpad.net/ubuntu/+source/samba/2:4.1.13+dfsg-4ubuntu3.1
  https://launchpad.net/ubuntu/+source/samba/2:4.1.6+dfsg-1ubuntu2.14.04.11
  https://launchpad.net/ubuntu/+source/samba/2:3.6.3-2ubuntu2.13