Protocol SSH1 is safe? I mean, if many users have access to a remote server on wich works a ssh server upgraded to the last patch, and i do it by mean of a ssh1 client (teraterm for example) may i be sure that the connection is safe or i must change to SSH2 protocol? Which type of attack may i expect as well than buffer-overflow? thanks in advance Teani Mauro Teani@osratoscana.it Tel. 0583 424700 Fax 0583 424750 http://www.osratoscana.it Il testo e gli eventuali documenti trasmessi contengono informazioni riservate al destinatario indicato. La seguente e-mail è confidenziale e la sua riservatezza è tutelata legalmente dal Decreto Legislativo 196 del 30/06/2003 (Codice di tutela della privacy). La lettura, copia o altro uso non autorizzato o qualsiasi altra azione derivante dalla conoscenza di queste informazioni sono rigorosamente vietate. Qualora abbiate ricevuto questo documento per errore siete cortesemente pregati di darne immediata comunicazione al mittente e di provvedere, immediatamente, alla sua distruzione.
Mauro Teani wrote:
Protocol SSH1 is safe? I mean, if many users have access to a remote server on wich works a ssh server upgraded to the last patch, and i do it by mean of a ssh1 client (teraterm for example) may i be sure that the connection is safe or i must change to SSH2 protocol? Which type of attack may i expect as well than buffer-overflow?
ssh v1 protocol is not secure any more, for quite some time now. try to switch to ssh v2 for example read 1.8 and 1.12 http://www.employees.org/~satch/ssh/faq/ssh-faq-1.html
Mauro Teani wrote:
Protocol SSH1 is safe? I mean, if many users have access to a remote server on wich works a ssh server upgraded to the last patch, and i do it by mean of a ssh1 client (teraterm for example) may i be sure that the connection is safe or i must change to SSH2 protocol? Which type of attack may i expect as well than buffer-overflow?
SSHv1 is vulnerable to man-in-the-middle attacks. It's not a matter of a buffer-overflow, but someone actually being able to decrypt and read the traffic. For windows machines, I recommend PuTTY: http://www.chiark.greenend.org.uk/~sgtatham/putty/ Linux machines, of course, should already have OpenSSH installed...
Why not use Putty instead?
Lyle
----- Original Message -----
From: "Mauro Teani"
Hi! SSH protocol v.1 is prone to man in the middle attacks. If you want to try it yourself use e.g. ettercap. http://freshmeat.net/projects/ettercap/ http://ettercap.sourceforge.net/ On Donnerstag 21 Oktober 2004 10:27, Mauro Teani wrote:
Protocol SSH1 is safe? I mean, if many users have access to a remote server on wich works a ssh server upgraded to the last patch, and i do it by mean of a ssh1 client (teraterm for example) may i be sure that the connection is safe or i must change to SSH2 protocol? Which type of attack may i expect as well than buffer-overflow?
thanks in advance
Have fun. -- Eat, sleep and go running, David Huecking. Encrypted eMail welcome! GnuPG/ PGP-Key: 0x57809216. Fingerprint: 3DF2 CBE0 DFAA 4164 02C2 4E2A E005 8DF7 5780 9216
I have an other important question.
If i use ssh1 with the RSA key (with the passphrase) i have the same security problem?
On Oct 21, 2004 10:44 AM, Andreas Bittner
Mauro Teani wrote:
Protocol SSH1 is safe? I mean, if many users have access to a remote server on wich works a ssh server upgraded to the last patch, and i do it by mean of a ssh1 client (teraterm for example) may i be sure that the connection is safe or i must change to SSH2 protocol? Which type of attack may i expect as well than buffer-overflow?
ssh v1 protocol is not secure any more, for quite some time now. try to switch to ssh v2
for example read 1.8 and 1.12 http://www.employees.org/~satch/ssh/faq/ssh-faq-1.html
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Cristian Del Carlo delcarlo@osratoscana.it Tel. 0583 424700 Fax 0583 424750 http://www.osratoscana.it Il testo e gli eventuali documenti trasmessi contengono informazioni riservate al destinatario indicato. La seguente e-mail è confidenziale e la sua riservatezza è tutelata legalmente dal Decreto Legislativo 196 del 30/06/2003 (Codice di tutela della privacy). La lettura, copia o altro uso non autorizzato o qualsiasi altra azione derivante dalla conoscenza di queste informazioni sono rigorosamente vietate. Qualora abbiate ricevuto questo documento per errore siete cortesemente pregati di darne immediata comunicazione al mittente e di provvedere, immediatamente, alla sua distruzione.
Cristian Del Carlo wrote:
I have an other important question. If i use ssh1 with the RSA key (with the passphrase) i have the same security problem?
i am not a technical expert for the ssh protocol, but as far as i have always heard, ssh v1 is vulnerable to man in the middle attacks as others also pointed out on the list. i guess its not dependant of the authentication means you use. migrate over to ssh v2 as soon as possible and you will be safer.
On Fri, 22 Oct 2004, Andreas Bittner wrote: Hi, SSHv1 is not insecure because it might be affected by MiM attacks (same can work for SSHv2, easier indeed) but because it has some short-comings in the protocol. Like the integrity of packets relies on a CRC32 sum which is not acceptable (versus a real has-sum in SSH2) anymore. For SSH1, a MiM is also possible for RSA authentication if I remember correctly, the SSH2 pubkey authentication is not MiM-able. So, in conculsion, use SSH2 plus pubkey authentication. :-) Sebastian
Cristian Del Carlo wrote:
I have an other important question. If i use ssh1 with the RSA key (with the passphrase) i have the same security problem?
i am not a technical expert for the ssh protocol, but as far as i have always heard, ssh v1 is vulnerable to man in the middle attacks as others also pointed out on the list. i guess its not dependant of the authentication means you use. migrate over to ssh v2 as soon as possible and you will be safer.
-- ~ ~ perl self.pl ~ $_='print"\$_=\47$_\47;eval"';eval ~ krahmer@suse.de - SuSE Security Team ~
Cristian Del Carlo wrote:
I have an other important question. If i use ssh1 with the RSA key (with the passphrase) i have the same security problem?
I believe the problem is in the negotiation, not in the authentication. Why would you even want to use SSHv1 at all? There are SSHv2 implementations freely available for every platform I can think of...
participants (7)
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Andreas Bittner -
Cristian Del Carlo -
David Huecking -
Lyle Giese -
Mauro Teani -
Sebastian Krahmer -
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