SecurityTracker.com
    Home    |    View Topics    |    Search    |    Contact Us    |   

SecurityTracker
Archives


 


Category:   Application (Security)  >   OpenSSH Vendors:   OpenSSH.org
(Turbo Linux Releases Fix) Re: Weaknesses in SSH Protocols Can Facilitate Attacks Through Passive Monitoring of Protocol Traffic
SecurityTracker Alert ID:  1001596
SecurityTracker URL:  http://securitytracker.com/id/1001596
CVE Reference:   GENERIC-MAP-NOMATCH   (Links to External Site)
Date:  May 23 2001
Impact:   Disclosure of authentication information, Disclosure of system information
Fix Available:  Yes  Vendor Confirmed:  Yes  

Description:   It was reported last week that several weaknesses exist in various implementations of SSH (Secure Shell) protocols. When exploited, these vulnerabilities let an attacker obtain sensitive information by passively monitoring encrypted SSH sessions that can later be used to facilitate attacks. This could include speeding up brute-force attacks on passwords, including the initial login password and other passwords appearing in interactive SSH sessions.

Version 1 of the SSH protocol generally exposes the exact lengths of login passwords used with password authentication. The SSH-2 protocol doesn't reveal as much information, but still presents a range of possible password lengths.

Additional weaknesses reportedly allow for detection of when a password is entered during an interactive SSH session and detection of the timing of the keying, which may expose the likelihood of possible characters in each position of a password. It is also reportedly possible to determine the lengths of shell commands.

For details, please read the source message.

Impact:   An attacker that is monitoring SSH traffic could obtain sensitive information that can later be used to facilitate attacks. This could include speeding up brute-force attacks on passwords, including the initial login password and other passwords appearing in interactive SSH sessions, such as those used with su(1) and Cisco IOS "enable" passwords.
Solution:   Turbo Linux has released a fix. See the Source Message for the Turbo Linux advisory.
Vendor URL:  www.openssh.org (Links to External Site)
Cause:   Authentication error, Randomization error
Underlying OS:  Linux (Turbo Linux)

Message History:   This archive entry is a follow-up to the message listed below.
Mar 27 2001 Weaknesses in SSH Protocols Can Facilitate Attacks Through Passive Monitoring of Protocol Traffic



 Source Message Contents

Subject:  [TL-Security-Announce] TLSA2001021 openssh-2.5.2p2-2


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1



_____________________________________________________________________________________________

                        Turbolinux Security Announcement

        Package:  openssh
        Vulnerable Packages: All Turbolinux versions prior to 2.5.2p2-2
        Date: 05/17/2001 5:00 PDT

        Affected Turbolinux platforms:  TL Server 6.5

        Turbolinux Advisory ID#:  TLSA2001021
        
        Credits:  Solar Designer < solar@openwall.com >
                  Dug Song <dugsong@monkey.org>
                  Markus Friedl and Theo de Raadt of OpenSSH
                  Simon Tatham (PuTTY), and Niels Mller (LSH) 

        Reference:  http://www.securityfocus.com/archive/1/169840

_____________________________________________________________________________________________

Several security holes were discovered in the package mentioned above.
Please update the packages in your installation as soon as possible.
_____________________________________________________________________________________________

1. Problem Summary

      Several weaknesses in the SSH protocol have been detected.  To capitalize on them, an
   attacker must have the means to sniff, or monitor, network traffic between one or more
   SSH clients and servers.  Exploiting these weaknesses would enable an attacker to determine
   passwords and shell commands more quickly during passive monitoring of password authenti-
   cation and interactive ssh sessions.  
      The weaknesses in the SSH protocol include revealing an approximate, or, in the case 
   of SSH1, an exact length of a password, or shell command.  It is also possible to gather
   timing information, which can expose the likelihood of possible characters in each posi-
   tion of a password.  Using compression in an attempt to "randomize" the length of pass-
   words does not help much since the size of the compressed data packets depends on the con-
   tents of the packets.


2. Solution

   Update the packages from our ftp server by using the following command:

	 rpm -Uvh ftp_path_to_filename

   Where ftp_path_to_filename is the following:

ftp://ftp.turbolinux.com/pub/updates/6.0/security/openssh-2.5.2p2-2.i386.rpm
ftp://ftp.turbolinux.com/pub/updates/6.0/security/openssh-askpass-2.5.2p2-2.i386.rpm
ftp://ftp.turbolinux.com/pub/updates/6.0/security/openssh-askpass-gnome-2.5.2p2-2.i386.rpm
ftp://ftp.turbolinux.com/pub/updates/6.0/security/openssh-clients-2.5.2p2-2.i386.rpm
ftp://ftp.turbolinux.com/pub/updates/6.0/security/openssh-server-2.5.2p2-2.i386.rpm

 The source RPM can be downloaded here:

  ftp://ftp.turbolinux.com/pub/updates/6.0/SRPMS/openssh-2.5.2p2-2.src.rpm

  **Note: You must rebuild and install the RPM if you choose to download
  and install the SRPM.  Simply installing the SRPM alone WILL NOT CLOSE
  THE SECURITY HOLE.

 Please verify the MD5 checksums of the updates before you install:

  MD5 sum                               Package Name
- ---------------------------------------------------------------------------------------------
           
  16212b406435bb3bfa3ad157bc27e94a      openssh-2.5.2p2-2.i386.rpm
  f3f499f9e9a052bdd2511ed0d28bb89a      openssh-askpass-2.5.2p2-2.i386.rpm
  3d348dffe8c985fac2dbc5e03a58cf00      openssh-askpass-gnome-2.5.2p2-2.i386.rpm
  cc59641605ac79ed24f51ebc0dde1325      openssh-clients-2.5.2p2-2.i386.rpm
  3682d87243e2fbe823cf9c892bf6cf21      openssh-server-2.5.2p2-2.i386.rpm
  f57ddc14e022638fd76bc76b17653291      openssh-2.5.2p2-2.src.rpm
_____________________________________________________________________________________________

These packages are GPG signed by Turbolinux for security. Our key
is available here:

 http://www.turbolinux.com/security/tlgpgkey.asc

To verify a package, use the following command:

 rpm --checksig name_of_rpm

To examine only the md5sum, use the following command:

 md5sum name_of_rpm

**Note: Checking GPG keys requires RPM 3.0 or higher.

_____________________________________________________________________________________________

You can find more updates on our ftp server:

   ftp://ftp.turbolinux.com/pub/updates/6.0/security/ 

for TL6.x Workstation and Server security updates
   
Our webpage for security announcements:

   http://www.turbolinux.com/security

If you want to report vulnerabilities, please contact:

   security@turbolinux.com
______________________________________________________________________________________________

Subscribe to the Turbolinux Security Mailing lists:

  TL-security - A moderated list for discussing security issues
                Turbolinux products.
  Subscribe at http://www.turbolinux.com/mailman/listinfo/tl-security

  TL-security-announce - An announce-only mailing list for security
                         updates and alerts.  Subscribe at:

      http://www.turbolinux.com/mailman/listinfo/tl-security-announce

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.4 (GNU/Linux)
Comment: pgpenvelope 2.10.0 - http://pgpenvelope.sourceforge.net/

iD8DBQE7Cx9ccpw52/ZatwoRAt2ZAJ0ajyt2+JeY1x812WTIUpIgBXO64ACfcQRx
zHDf9HaFVWltY2HuYSANayA=
=UrYl
-----END PGP SIGNATURE-----



_______________________________________________
TL-Security-Announce mailing list
TL-Security-Announce@www.turbolinux.com
http://www.turbolinux.com/mailman/listinfo/tl-security-announce

 
 


Go to the Top of This SecurityTracker Archive Page





Home   |    View Topics   |    Search   |    Contact Us

This web site uses cookies for web analytics. Learn More

Copyright 2020, SecurityGlobal.net LLC