USN-649-1: OpenSSH vulnerabilities

Ubuntu Security Notice USN-649-1

1st October, 2008

openssh vulnerabilities

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

  • Ubuntu 7.10
  • Ubuntu 7.04
  • Ubuntu 6.06 LTS

Software description

  • openssh


It was discovered that the ForceCommand directive could be bypassed.
If a local user created a malicious ~/.ssh/rc file, they could execute
arbitrary commands as their user id. This only affected Ubuntu 7.10.

USN-355-1 fixed vulnerabilities in OpenSSH. It was discovered that the
fixes for this issue were incomplete. A remote attacker could attempt
multiple logins, filling all available connection slots, leading to a
denial of service. This only affected Ubuntu 6.06 and 7.04.

Update instructions

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

Ubuntu 7.10:
openssh-server 1:4.6p1-5ubuntu0.6
Ubuntu 7.04:
openssh-server 1:4.3p2-8ubuntu1.5
Ubuntu 6.06 LTS:
openssh-server 1:4.2p1-7ubuntu3.5

To update your system, please follow these instructions:

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


CVE-2008-1657, CVE-2008-4109