USN-544-2: Samba regression

16 November 2007

samba regression

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

  • Ubuntu 7.10
  • Ubuntu 7.04
  • Ubuntu 6.10
  • Ubuntu 6.06 LTS

Software Description

  • samba

Details

USN-544-1 fixed two vulnerabilities in Samba. Fixes for CVE-2007-5398 are unchanged, but the upstream changes for CVE-2007-4572 introduced a regression in all releases which caused Linux smbfs mounts to fail. Additionally, Dapper and Edgy included an incomplete patch which caused configurations using NetBIOS to fail. A proper fix for these regressions does not exist at this time, and so the patch addressing CVE-2007-4572 has been removed. This vulnerability is believed to be an unexploitable denial of service, but a future update will address this issue. We apologize for the inconvenience.

Original advisory details:

Samba developers discovered that nmbd could be made to overrun a buffer during the processing of GETDC logon server requests. When samba is configured as a Primary or Backup Domain Controller, a remote attacker could send malicious logon requests and possibly cause a denial of service. (CVE-2007-4572)

Alin Rad Pop of Secunia Research discovered that nmbd did not properly check the length of netbios packets. When samba is configured as a WINS server, a remote attacker could send multiple crafted requests resulting in the execution of arbitrary code with root privileges. (CVE-2007-5398)

Update instructions

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

Ubuntu 7.10
samba - 3.0.26a-1ubuntu2.2
Ubuntu 7.04
samba - 3.0.24-2ubuntu1.4
Ubuntu 6.10
samba - 3.0.22-1ubuntu4.4
Ubuntu 6.06 LTS
samba - 3.0.22-1ubuntu3.5

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

In general, a standard system upgrade is sufficient to effect the necessary changes.

References