Updated openssh packages that fix a potential security vulnerability and various other bugs are now available for Red Hat Enterprise Linux 3. This update has been rated as having low security impact by the Red Hat Security Response Team.
OpenSSH is OpenBSD's SSH (Secure SHell) protocol implementation. SSH replaces rlogin and rsh, and provides secure encrypted communications between two untrusted hosts over an insecure network. X11 connections and arbitrary TCP/IP ports can also be forwarded over a secure channel. Public key authentication can be used for "passwordless" access to servers. The scp protocol allows a server to instruct a client to write to arbitrary files outside of the current directory. This could potentially cause a security issue if a user uses scp to copy files from a malicious server. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2004-0175 to this issue. These updated packages also correct the following bugs: On systems where direct ssh access for the root user was disabled by configuration (setting "PermitRootLogin no"), attempts to guess the root password could be judged as sucessful or unsucessful by observing a delay. On systems where the privilege separation feature was turned on, the user resource limits were not correctly set if the configuration specified to raise them above the defaults. It was also not possible to change an expired password. Users of openssh should upgrade to these updated packages, which contain backported patches to resolve these issues.