USN-1640-1: libssh vulnerabilities

Ubuntu Security Notice USN-1640-1

26th November, 2012

libssh vulnerabilities

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

  • Ubuntu 12.10
  • Ubuntu 12.04 LTS
  • Ubuntu 11.10
  • Ubuntu 10.04 LTS


linssh could be made to crash or run programs if it received specially crafted network traffic.

Software description

  • libssh - A tiny C SSH library


Xi Wang and Florian Weimer discovered that libssh incorrectly handled
memory. A remote attacker could use this to cause libssh to crash,
resulting in a denial of service, or possibly execute arbitrary code.
(CVE-2012-4559, CVE-2012-4560, CVE-2012-4561, CVE-2012-4562)

Update instructions

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

Ubuntu 12.10:
libssh-4 0.5.2-1ubuntu0.12.10.1
Ubuntu 12.04 LTS:
libssh-4 0.5.2-1ubuntu0.12.04.1
Ubuntu 11.10:
libssh-4 0.5.2-1ubuntu0.11.10.1
Ubuntu 10.04 LTS:
libssh-4 0.4.2-1ubuntu1.1

To update your system, please follow these instructions:

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


CVE-2012-4559, CVE-2012-4560, CVE-2012-4561, CVE-2012-4562