Updated openssh packages are now available for Red Hat Linux 7. These packages reduce the amount of information a passive attacker can deduce from observing an encrypted session. `

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                   Red Hat, Inc. Red Hat Security Advisory

Synopsis:          Updated openssh packages available
Advisory ID:       RHSA-2001:033-04
Issue date:        2001-03-23
Updated on:        2001-03-27
Product:           Red Hat Linux
Keywords:          openssh passive analysis
Cross references:  
Obsoletes:         RHBA-2000-076 RHSA-2000-111
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1. Topic:

Updated openssh packages are now available for Red Hat Linux 7.  These
packages reduce the amount of information a passive attacker can deduce
from observing an encrypted session.

2. Relevant releases/architectures:

Red Hat Linux 7.0 - alpha, i386

3. Problem description:

Weaknesses in the SSH protocols can be used by a passive attacker to deduce
information about passwords entered over an encrypted connection.  This
information can be used to reduce the number of possible solutions which
need to be tested to perform a brute-force attack. This reduces the amount
of time and resources required to mount such an attack successfully.

OpenSSH 2.5.1 and 2.5.2 include modifications which, while not completely
resolving this problem, reduce the risks by changing certain server
behaviors to make passive analysis more difficult.

4. Solution:

To update all RPMs for your particular architecture, run:

rpm -Fvh [filenames]

where [filenames] is a list of the RPMs you wish to upgrade.  Only those
RPMs which are currently installed will be updated.  Those RPMs which are
not installed but included in the list will not be updated.  Note that you
can also use wildcards (*.rpm) if your current directly *only* contains the
desired RPMs.

Please note that this update is also available via Red Hat Network.  Many
people find this an easier way to apply updates.  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.

5. Bug IDs fixed  (  for more info):

30293 - Where is sftp?
32977 - ssh unable to connect to certain servers using v2

6. RPMs required:

Red Hat Linux 7.0:

SRPMS: 
 

alpha: 
  
  
  
  
 

i386: 
  
  
  
  
 



7. Verification:

MD5 sum                           Package Name
--------------------------------------------------------------------------
2249d15ecdca22482c03e8059dd8b31d  7.0/SRPMS/openssh-2.5.2p2-1.7.src.rpm
2c1705e525c6f07d611520374ddfe451  7.0/alpha/openssh-2.5.2p2-1.7.alpha.rpm
da69ea875b494a81b91caa65bad4b3b0  7.0/alpha/openssh-askpass-2.5.2p2-1.7.alpha.rpm
52f445b91c77c4aa1e63624aaca56a2a  7.0/alpha/openssh-askpass-gnome-2.5.2p2-1.7.alpha.rpm
997f39e0755a36d7633e6ddbde8b5e5d  7.0/alpha/openssh-clients-2.5.2p2-1.7.alpha.rpm
df2d8919c4c2ff8b0a57a4826c20e764  7.0/alpha/openssh-server-2.5.2p2-1.7.alpha.rpm
59fe7436fb6736b7948bfaec706c5628  7.0/i386/openssh-2.5.2p2-1.7.i386.rpm
f80b1952bd5caf65d0e724a26b421635  7.0/i386/openssh-askpass-2.5.2p2-1.7.i386.rpm
04723384928efd09e4f96ef142409135  7.0/i386/openssh-askpass-gnome-2.5.2p2-1.7.i386.rpm
8e387b44bd433e71c1caecb899a680f4  7.0/i386/openssh-clients-2.5.2p2-1.7.i386.rpm
99a219f6c0708203f4982a4998b4e401  7.0/i386/openssh-server-2.5.2p2-1.7.i386.rpm

These packages are GPG signed by Red Hat, Inc. for security.  Our key
is available at:
      

You can verify each package with the following command:
    rpm --checksig  

If you only wish to verify that each package has not been corrupted or
tampered with, examine only the md5sum with the following command:
    rpm --checksig --nogpg 

8. References:
 
Passive Analysis of SSH (Secure Shell) Traffic 
http://marc.theaimsgroup.com/?l=openssh-unix-dev&m=98525792903526&w=2 
http://marc.theaimsgroup.com/?l=openssh-unix-dev&m=98527416918430&w=2


Copyright(c) 2000, 2001 Red Hat, Inc.

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