USN-544-2: Samba regression

Ubuntu Security Notice USN-544-2

16th 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 version:

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

CVE-2007-4572, LP: 163042