RHSA-2005:527 - Security Advisory

Topic

Updated openssh packages that fix a security issue, bugs, and add support
for recording login user IDs for audit are now available for Red Hat
Enterprise Linux 4.

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

Description

OpenSSH is OpenBSD's SSH (Secure SHell) protocol implementation.

An error in the way OpenSSH handled GSSAPI credential delegation was
discovered. OpenSSH as distributed with Red Hat Enterprise Linux 4 contains
support for GSSAPI user authentication, typically used for supporting
Kerberos. On OpenSSH installations which have GSSAPI enabled, this flaw
could allow a user who sucessfully authenticates using a method other than
GSSAPI to be delegated with GSSAPI credentials. The Common Vulnerabilities
and Exposures project (cve.mitre.org) has assigned the name CAN-2005-2798
to this issue.

Additionally, the following bugs have been addressed:

The ssh command incorrectly failed when it was issued by the root user with
a non-default group set.

The sshd daemon could fail to properly close the client connection if
multiple X clients were forwarded over the connection and the client
session exited.

The sshd daemon could bind only on the IPv6 address family for X forwarding
if the port on IPv4 address family was already bound. The X forwarding did
not work in such cases.

This update also adds support for recording login user IDs for the auditing
service. The user ID is attached to the audit records generated from the
user's session.

All users of openssh should upgrade to these updated packages, which
contain backported patches to resolve these issues.

Solution

Before applying this update, make sure that all previously-released
errata relevant to your system have been applied. Use Red Hat
Network to download and update your packages. To launch the Red Hat
Update Agent, use the following command:

up2date

For information on how to install packages manually, refer to the
following Web page for the System Administration or Customization
guide specific to your system:

http://www.redhat.com/docs/manuals/enterprise/

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 Workstation 4 x86_64
• Red Hat Enterprise Linux Workstation 4 ia64
• Red Hat Enterprise Linux Workstation 4 i386
• Red Hat Enterprise Linux Desktop 4 x86_64
• Red Hat Enterprise Linux Desktop 4 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 Power, big endian 4 ppc

Fixes

• BZ - 159331 - sshd update for new audit system
• BZ - 167444 - CAN-2005-2798 Improper GSSAPI credential delegation

CVEs

• CVE-2005-2798
• CVE-2008-1483

References

(none)