9.3 - RHSA-2006:0698

Problem Description:

Updated openssh packages that fix several security issues in sshd are now available for Red Hat Enterprise Linux 2.1.

This update has been rated as having important security impact by the Red Hat Security Response Team.

2. Relevant releases/architectures:

Red Hat Enterprise Linux AS (Advanced Server) version 2.1 - i386, ia64 Red Hat Linux Advanced Workstation 2.1 - ia64 Red Hat Enterprise Linux ES version 2.1 - i386 Red Hat Enterprise Linux WS version 2.1 - i386

3. Problem description:

OpenSSH is OpenBSD's SSH (Secure SHell) protocol implementation. This package includes the core files necessary for both the OpenSSH client and server.

Mark Dowd discovered a signal handler race condition in the OpenSSH sshd server. A remote attacker could possibly leverage this flaw to cause a denial of service (crash). (CVE-2006-5051) The OpenSSH project believes the likelihood of successful exploitation leading to arbitrary code execution appears remote. However, the Red Hat Security Response Team have not yet been able to verify this claim due to lack of upstream vulnerability information. We are therefore including a fix for this flaw and have rated it important security severity in the event our continued investigation finds this issue to be exploitable.

Tavis Ormandy of the Google Security Team discovered a denial of service bug in the OpenSSH sshd server. A remote attacker can send a specially crafted SSH-1 request to the server causing sshd to consume a large quantity of CPU resources. (CVE-2006-4924)

An arbitrary command execution flaw was discovered in the way scp copies files locally. It is possible for a local attacker to create a file with a carefully crafted name that could execute arbitrary commands as the user running scp to copy files locally. (CVE-2006-0225)

The SSH daemon, when restricting host access by numeric IP addresses and with VerifyReverseMapping disabled, allows remote attackers to bypass "from=" and "user@host" address restrictions by connecting to a host from a system whose reverse DNS hostname contains the numeric IP address. (CVE-2003-0386)

All users of openssh should upgrade to these updated packages, which contain backported patches that resolve these issues.

4. Solution:

Before applying this update, make sure all previously released errata relevant to your system have been applied.

This update is available via Red Hat Network. To use Red Hat Network, launch the Red Hat Update Agent with the following command:

up2date

This will start an interactive process that will result in the appropriate RPMs being upgraded on your system.

5. Bug IDs fixed (http://bugzilla.redhat.com/):

174026 - CVE-2006-0225 local to local copy uses shell expansion twice 208248 - CVE-2003-0386 host based access bypass 208298 - CVE-2006-4924 openssh DoS 208430 - CVE-2006-5051 unsafe GSSAPI signal handler