High Nessus Plugin ID 13806
SynopsisThe remote host is missing a vendor-supplied security patch
DescriptionThe remote host is missing the patch for the advisory SUSE-SA:2003:038 (openssh).
The openssh package is the most widely used implementation of the secure shell protocol family (ssh). It provides a set of network connectivity tools for remote (shell) login, designed to substitute the traditional BSD-style r-protocols (rsh, rlogin). openssh has various authentification mechanisms and many other features such as TCP connection and X11 display forwarding over the fully encrypted network connection as well as file transfer facilities.
A programming error has been found in code responsible for buffer management. If exploited by a (remote) attacker, the error may lead to unauthorized access to the system, allowing the execution of arbitrary commands.
The error is known as the buffer_append_space()-bug and is assigned the Common Vulnerabilities and Exposures (CVE) name CVE-2003-0693.
At the time of writing this announcement, it is unclear if the buffer_append_space()-bug is exploitable. However, an increasing amount of TCP connection attempts to port 22 (the ssh default port) has been observed in the internet during the past days, which may indicate that there exists an exploit for the error.
Please note that we have disabled the Privilege Separation feature in the ssh daemon (sshd) with this update. The PrivSep feature is designed to have parts of the ssh daemon's work running under lowered privileges, thereby limiting the effect of a possible vulnerability in the code. The PrivSep feature is turned on/off by the UsePrivilegeSeparation keyword in sshd's configuration file /etc/ssh/sshd_config. The feature is held responsible for malfunctions in PAM (Pluggable Authentification Modules).
The update mechanism will not overwrite configuration files that have been altered after the package installation.