OpenSSH is _not_ vulnerable the several known problems in SSH-1 (fwd)

J. Kyllo jjkyllo at u.washington.edu
Sun Feb 18 18:14:47 PST 2001


To use openssh with glibc 2.2, you can get the rpms from
ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/rpm

It seems that the permissions are funky right now but they might be on
rpmfind.net. Anyway, it's all there. If someone would like me to post
them somewhere, I have them.

-Jeff


On Sat, 17 Feb 2001, Dave Dittrich wrote:


> FYI. OpenSSH comes default with Red Hat Linux 7.0. I still haven't

> figured out all the RPMs that must be updated to use it on RH 6.2 or

> less. (It relies on GLIBC 2.2 and some other stuff that isn't trivial

> to update.)

>

> --

> Dave Dittrich Computing & Communications

> dittrich at cac.washington.edu Client Services

> http://staff.washington.edu/dittrich University of Washington

>

> PGP key http://staff.washington.edu/dittrich/pgpkey.txt

> Fingerprint FE 97 0C 57 08 43 F3 EB 49 A1 0C D0 8E 0C D0 BE C8 38 CC B5

>

> ---------- Forwarded message ----------

> Date: Thu, 15 Feb 2001 09:13:41 +0100

> Subject: OpenSSH is _not_ vulnerable the several known problems in SSH-1

> From: Markus Friedl <Markus.Friedl at informatik.uni-erlangen.de>

> To: openssh-unix-dev at mindrot.org, ssh at clinet.fi, security-announce at openbsd.org,

> misc at openbsd.org

> Cc: bugtraq at securityfocus.com

>

> -----------------------------------------------------------------------

>

> Special OpenBSD Security Note

>

> February 14, 2001

>

> OpenSSH is _not_ vulnerable the several known problems in SSH-1

>

> -----------------------------------------------------------------------

>

> The CERT Coordination Center has published the following notes about

> weaknesses in various SSH protocol version 1 implementations.

>

> Since many people using OpenSSH are worried about these issues,

> we decided to publish these notes.

>

> 1) http://www.kb.cert.org/vuls/id/565052

> "Passwords sent via SSH encrypted with RC4 can be easily cracked"

>

> 2) http://www.kb.cert.org/vuls/id/665372

> "SSH connections using RC4 and password authentication can be

> replayed"

>

> 3) http://www.kb.cert.org/vuls/id/25309

> "Weak CRC allows RC4 encrypted SSH packets to be modified without

> notice"

>

> 4) http://www.kb.cert.org/vuls/id/684820

> "SSH allows client authentication to be forwarded if encryption

> is disabled"

>

> 5) http://www.kb.cert.org/vuls/id/315308

> "Last block of IDEA-encrypted SSH packet can be changed without

> notice"

>

> 6) http://www.kb.cert.org/vuls/id/786900

> "SSH host key authentication can be bypassed when DNS is used

> to resolve localhost"

>

> 7) http://www.kb.cert.org/vuls/id/118892

> "Older SSH clients do not allow users to disable X11 forwarding"

>

> OpenSSH is _not_ vulnerable to #1, #2 and #3 since OpenSSH does not

> allow RC4 in its SSH protocol 1 implementation.

>

> OpenSSH is _not_ vulnerable to #4 since OpenSSH does not allow

> encryption to be disabled.

>

> OpenSSH is _not_ vulnerable to #5 since OpenSSH does not support

> IDEA.

>

> OpenSSH is _not_ vulnerable to #6 since OpenSSH does not resolve

> "localhost". OpenSSH uses the resolved IP-address and disables the

> host key authentication for 127.0.0.1 only.

>

> OpenSSH is _not_ vulnerable to #7 since OpenSSH permits users to

> disable X11 forwarding, and this is the default configuration in

> the OpenSSH client.

>

> The SSH protocol version 2 (a.k.a. SecSH) is not affected by problems

> #1, #2, #3, #4 and #5.

>

> The OpenSSH client currenly defaults to preferring SSH-1 protocol

> over SSH-2 protocol, but in a future release the default will soon

> change, since the SSH-2 protocol support has improved considerably.

>

> -----------------------------------------------------------------------

>

>

>




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