OpenSSH: Denial of Service

2006-09-27T00:00:00
ID GLSA-200609-17
Type gentoo
Reporter Gentoo Foundation
Modified 2006-09-27T00:00:00

Description

Background

OpenSSH is a free suite of applications for the SSH protocol, developed and maintained by the OpenBSD project.

Description

Tavis Ormandy of the Google Security Team discovered a Denial of Service vulnerability in the SSH protocol version 1 CRC compensation attack detector.

Impact

A remote unauthenticated attacker may be able to trigger excessive CPU usage by sending a pathological SSH message, denying service to other legitimate users or processes.

Workaround

The system administrator may disable SSH protocol version 1 in /etc/ssh/sshd_config.

Resolution

All OpenSSH users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=net-misc/openssh-4.3_p2-r5"