RHSA-2006:0738 - Security Advisory

Topic

Updated openssh packages that fix an authentication flaw are now available
for Red Hat Enterprise Linux 3 and 4.

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

Description

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

An authentication flaw was found in OpenSSH's privilege separation monitor.
If it ever becomes possible to alter the behavior of the unprivileged
process when OpenSSH is using privilege separation, an attacker may then be
able to login without possessing proper credentials. (CVE-2006-5794)

Please note that this flaw by itself poses no direct threat to OpenSSH
users. Without another security flaw that could allow an attacker to alter
the behavior of OpenSSH's unprivileged process, this flaw cannot be
exploited. There are currently no known flaws to exploit this behavior.
However, we have decided to issue this erratum to fix this flaw to reduce
the security impact if an unprivileged process flaw is ever found.

Users of openssh should upgrade to these updated packages, which contain a
backported patch to resolve this issue.

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.

Affected Products

• Red Hat Enterprise Linux Server 4 x86_64
• Red Hat Enterprise Linux Server 4 ia64
• Red Hat Enterprise Linux Server 4 i386
• Red Hat Enterprise Linux Server 3 x86_64
• Red Hat Enterprise Linux Server 3 ia64
• Red Hat Enterprise Linux Server 3 i386
• Red Hat Enterprise Linux Workstation 4 x86_64
• Red Hat Enterprise Linux Workstation 4 ia64
• Red Hat Enterprise Linux Workstation 4 i386
• Red Hat Enterprise Linux Workstation 3 x86_64
• Red Hat Enterprise Linux Workstation 3 ia64
• Red Hat Enterprise Linux Workstation 3 i386
• Red Hat Enterprise Linux Desktop 4 x86_64
• Red Hat Enterprise Linux Desktop 4 i386
• Red Hat Enterprise Linux Desktop 3 x86_64
• Red Hat Enterprise Linux Desktop 3 i386
• Red Hat Enterprise Linux for IBM z Systems 4 s390x
• Red Hat Enterprise Linux for IBM z Systems 4 s390
• Red Hat Enterprise Linux for IBM z Systems 3 s390x
• Red Hat Enterprise Linux for IBM z Systems 3 s390
• Red Hat Enterprise Linux for Power, big endian 4 ppc
• Red Hat Enterprise Linux for Power, big endian 3 ppc

Fixes

• BZ - 214640 - CVE-2006-5794 OpenSSH privilege separation flaw

CVEs

• CVE-2006-5794

References

• http://www.redhat.com/security/updates/classification/#low