RHBA-2005:046 - Bug Fix Advisory

Topic

Updated openssh packages that fix a bug in sshd and change a default type
of X11 forwarding are now available for Red Hat Enterprise Linux 4.

Description

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

When authenticating incoming connections, sshd sets up a timeout using the
SIGALRM signal to limit the amount of time which an unauthenticated user
can keep a connection open. If the timeout was reached while sshd was
logging a message via syslog, sshd would deadlock.

The openssh-3.9p1 package adds X11 untrusted forwarding, which disables
access to many functionalities of the forwarded X11 display. This should
improve security, although few X11 client applications are fully functional
with this extension. This update sets the default type to trusted X11
forwarding.

All users of openssh should upgrade to these updated packages, which
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 - 150262 - SSH client should use trusted X forwarding by default if asked for X forwarding

CVEs

(none)

References

(none)