Synopsis:	Low: openssh security, bug fix, and enhancement update
Issue date:	2009-09-02
CVE Names:	CVE-2008-5161

CVE-2008-5161 OpenSSH: Plaintext Recovery Attack against CBC ciphers

A flaw was found in the SSH protocol. An attacker able to perform a
man-in-the-middle attack may be able to obtain a portion of plain text 
from an arbitrary ciphertext block when a CBC mode cipher was used to 
encrypt SSH communication. This update helps mitigate this attack: 
OpenSSH clients and servers now prefer CTR mode ciphers to CBC mode, and 
the OpenSSH server now reads SSH packets up to their full possible 
length when corruption is detected, rather than reporting errors early, 
reducing the possibility of successful plain text recovery. (CVE-2008-5161)

This update also fixes the following bug:

* the ssh client hung when trying to close a session in which a 
background process still held tty file descriptors open. With this 
update, this so-called "hang on exit" error no longer occurs and the ssh 
client closes the session immediately. (BZ#454812)

In addition, this update adds the following enhancements:

* the SFTP server can now chroot users to various directories, including
a user's home directory, after log in. A new configuration option --
ChrootDirectory -- has been added to "/etc/ssh/sshd_config" for setting
this up (the default is not to chroot users). Details regarding 
configuring this new option are in the sshd_config(5) manual page. 
(BZ#440240)

* the executables which are part of the OpenSSH FIPS module which is 
being validated will check their integrity and report their FIPS mode 
status to the system log or to the terminal. (BZ#467268, BZ#492363)

After installing this update, the OpenSSH server daemon (sshd) will be 
restarted automatically.

Note: fipscheck update needed for dependencies.

SL 5.x

     SRPMS:
openssh-4.3p2-36.el5.src.rpm
fipscheck-1.2.0-1.el5.src.rpm
     i386:
fipscheck-1.2.0-1.el5.i386.rpm
fipscheck-devel-1.2.0-1.el5.i386.rpm
fipscheck-lib-1.2.0-1.el5.i386.rpm
openssh-4.3p2-36.el5.i386.rpm
openssh-askpass-4.3p2-36.el5.i386.rpm
openssh-clients-4.3p2-36.el5.i386.rpm
openssh-server-4.3p2-36.el5.i386.rpm
     x86_64:
fipscheck-1.2.0-1.el5.i386.rpm
fipscheck-devel-1.2.0-1.el5.i386.rpm
fipscheck-lib-1.2.0-1.el5.i386.rpm
openssh-4.3p2-36.el5.i386.rpm
openssh-askpass-4.3p2-36.el5.i386.rpm
openssh-clients-4.3p2-36.el5.i386.rpm
openssh-server-4.3p2-36.el5.i386.rpm

-Connie Sieh
-Troy Dawson