USN-3158-1: Samba vulnerabilities

Releases

• Ubuntu 16.10
• Ubuntu 16.04 ESM
• Ubuntu 14.04 ESM
• Ubuntu 12.04

Packages

• 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)

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

• 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

• 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

• 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.

References

• CVE-2016-2123
• CVE-2016-2125
• CVE-2016-2126