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Security update for OpenSSH

Knowledgebase

(Last modified: 16SEP2003)


solutions Security update for OpenSSH SuSE Linux Maintenance Web (a1b94c8b5da0188997516c960ed592d1)

Applies to

Product(s): SuSE eMail Server 3.1
SuSE eMail Server III
SuSE Firewall Adminhost VPN
SuSE Linux Admin-CD for Firewall
SuSE Firewall on CD 2 - VPN
SuSE Firewall on CD 2
SuSE Linux Connectivity Server
SuSE Linux Enterprise Server 7 for IA32
SuSE Linux Enterprise Server 7 for IA64
SuSE Linux Enterprise Server 7 for PowerPC
SuSE Linux Enterprise Server 7 for S/390 and zSeries
SuSE Linux Enterprise Server 7 for IBM zSeries
SuSE Linux Enterprise Server 8 for x86
SuSE Linux Enterprise Server 8 for IBM iSeries and IBM pSeries
SuSE Linux Enterprise Server 8 for IBM S/390 and IBM zSeries
SuSE Linux Enterprise Server 8 for IBM zSeries
SuSE Linux Office Server
SuSE Linux Openexchange Server 4
SuSE Linux Enterprise Server 8 for IPF
SuSE Linux Enterprise Server 8 for AMD64
SuSE Linux Desktop 1.0
SuSE Linux Standard Server 8

Package: openssh
Release: 20030916
Obsoletes: none

Indications

This update should be installed on all systems that have a running ssh dÆmon (this is the default).

Contraindications

None.

Problem description

OpenSSH is the most widely used implementation of the Secure Shell (SSH) protocol family. SSH provides an easy to use facility for encrypted remote shell login, TCP-connection- and X11-connection forwarding and is designed to substitute the BSD-style R-protocols (rlogin, rsh).
The package is installed on most SuSE products, and the SSH dÆmon (sshd, the ssh server) is activated by default on most SuSE systems to allow for secure remote administration of a system.
A coding error has been found in all currently supported versions of the OpenSSH package. This error may result in a vulnerability that may allow a remote attacker to execute arbitrary commands on the system running the sshd SSH server. It is yet unclear if the bugs discovered can be exploited by a remote attacker - however, an increasing amount of TCP connection attempts to the SSH port (22) has been noticed during the last few days. This may indicate that an exploit exists on the Internet.
The potential vulnerability is known as the buffer_append_space() bug and is assigned the Common Vulnerabilities and Exposures project name CAN-2003-0693.
In addition to the fix for the buffer_append_space() bug, this update turns off the Privilege Separation feature (See the option UsePrivilegeSeparation in the sshd global configuration file /etc/ssh/sshd_config). The feature was to blame for various inconsistencies in PAM authentication mechanisms and features that are incompatible with the Privilege Separation feature. If you have modified the sshd_config file that comes with the package, your configuration will not get overwritten by the update package.
It is highly recommended to install this update package on all systems that have an OpenSSH dÆmon (sshd) running.

Solution

Please install the updates provided at the location noted below.

Installation notes

This update is provided as an RPM package that can easily be installed onto a running system by using this command:
rpm -Fvh openssh.rpm
After performing the update, it is necessary to restart the sshd secure shell dÆmon. To do this, run the following command as user root:
rcsshd restart
Already running instances with established (legitimate) ssh connections should not be influenced and should continue to run.

links to download packages

Download Source Packages

Download the source code of the patches for maintained products.


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