Yong Chuan Koh discovered that libssh incorrectly handled certain negotiation requests. A remote attacker could use this to cause libssh to crash, resulting in a denial of service.
Updated packages are available from security.ubuntu.com.
========================================================================== Ubuntu Security Notice USN-1707-1 January 28, 2013 libssh vulnerability ========================================================================== 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 Summary: libssh could be made to crash if it received specially crafted network traffic. Software Description: - libssh: A tiny C SSH library Details: Yong Chuan Koh discovered that libssh incorrectly handled certain negotiation requests. A remote attacker could use this to cause libssh to crash, resulting in a denial of service. Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 12.10: libssh-4 0.5.2-1ubuntu0.12.10.2 Ubuntu 12.04 LTS: libssh-4 0.5.2-1ubuntu0.12.04.2 Ubuntu 11.10: libssh-4 0.5.2-1ubuntu0.11.10.2 Ubuntu 10.04 LTS: libssh-4 0.4.2-1ubuntu1.2 In general, a standard system update will make all the necessary changes. References: http://www.ubuntu.com/usn/usn-1707-1 CVE-2013-0176 Package Information: https://launchpad.net/ubuntu/+source/libssh/0.5.2-1ubuntu0.12.10.2 https://launchpad.net/ubuntu/+source/libssh/0.5.2-1ubuntu0.12.04.2 https://launchpad.net/ubuntu/+source/libssh/0.5.2-1ubuntu0.11.10.2 https://launchpad.net/ubuntu/+source/libssh/0.4.2-1ubuntu1.2