OpenSSH is OpenBSD's SSH (Secure Shell) protocol implementation. These packages include the core files necessary for both the OpenSSH client and server.
A Red Hat specific patch used in the openssh packages as shipped in Red Hat Enterprise Linux 5.4 (RHSA-2009:1287) loosened certain ownership requirements for directories used as arguments for the ChrootDirectory configuration options. A malicious user that also has or previously had non-chroot shell access to a system could possibly use this flaw to escalate their privileges and run commands as any system user. (CVE-2009-2904)
All OpenSSH users are advised to upgrade to these updated packages, which contain a backported patch to resolve this issue. After installing this update, the OpenSSH server daemon (sshd) will be restarted automatically.