Ubuntu: 3158-1 Moderate: Samba Security Issues and Risks

ubuntu

December 19, 2016

Several security issues were fixed in Samba.

Summary

Several security issues were fixed in Samba.

Software Description:

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

Details:

Frederic Besler and others discovered that the ndr_pull_dnsp_nam

function in Samba contained an integer overflow. An authenticated

attacker could use this to gain administrative privileges. This issue

only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, and Ubuntu 16.10.

(CVE-2016-2123)

Simo Sorce discovered that that Samba clients always requested

a forwardable ticket when using Kerberos authentication. An

attacker could use this to impersonate an authenticated user or

service. (CVE-2016-2125)

Volker Lendecke discovered that Kerberos PAC validation implementation

in Samba contained multiple vulnerabilities. An authenticated attacker

could use this to cause a denial of service or gain administrative

privileges. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04

LTS, and Ubuntu 16.10. (CVE-2016-2126)

Topics Covered

security advisory moderate denial of service security update Ubuntu Samba administrative access

Update Instructions

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

Ubuntu 16.10:
  libsmbclient                    2:4.4.5+dfsg-2ubuntu5.2
  samba                           2:4.4.5+dfsg-2ubuntu5.2
  winbind                         2:4.4.5+dfsg-2ubuntu5.2

Ubuntu 16.04 LTS:
  libsmbclient                    2:4.3.11+dfsg-0ubuntu0.16.04.3
  samba                           2:4.3.11+dfsg-0ubuntu0.16.04.3
  winbind                         2:4.3.11+dfsg-0ubuntu0.16.04.3

Ubuntu 14.04 LTS:
  libsmbclient                    2:4.3.11+dfsg-0ubuntu0.14.04.4
  samba                           2:4.3.11+dfsg-0ubuntu0.14.04.4
  winbind                         2:4.3.11+dfsg-0ubuntu0.14.04.4

Ubuntu 12.04 LTS:
  libsmbclient                    2:3.6.25-0ubuntu0.12.04.5
  samba                           2:3.6.25-0ubuntu0.12.04.5

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