full-disclosure - Possible DOS issue in OpenSSH ssh client

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Message-ID: <448EE64F.4040106@utdallas.edu>
Date: Tue Jun 13 17:23:37 2006
From: pauls at utdallas.edu (Paul Schmehl)
Subject: Possible DOS issue in OpenSSH ssh client

Espen Gr?ndahl wrote:
> During some testing I found a possible bug/issue with OpenSSH ssh client.
> 
> MachineA # cat < /dev/zero | nc ?l ?p 3000
> 
> MachineB# ssh someone@...hineA ?p 3000
>
> I have tested on OpenBSD 3.9, CentOS 4.3, Debian 3.1 and Solaris 9.
> 
> This consumes 50-100% of available CPU time on MachineB ( depending on the
> bandwith between them ).
> 
What did the ssh client do?  Did it eventually time out (as you would 
expect)?  Or did it hang and never disconnect?

-- 
Paul Schmehl (pauls@...allas.edu)
Adjunct Information Security Officer
The University of Texas at Dallas
http://www.utdallas.edu/ir/security/
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