data loss with ssh -n

[Dan Kaminsky]

> The server is SSH 1.2.25 or the like (yeah, I know it's broken, but can't
> be changed at the moment).

Wellllll...there's this cute little trick that works because of SSHD's
blissful lack of root dependancy:

ssh -o 'ProxyCommand ssh user at host openssh/sshd -i' user at host

Two conclusions to reach from this trick:

1) I have way too much fun with ProxyCommand
2) Unless you give a user a *really* restricted shell, sshd_config will
*never* be the right place to put your security constraints.

As for the larger issues...does the incorrect buffering behavior still
manifest itself without the -n?  In SSH1 and SSH2?  With and without TTY?

Yours Truly,

    Dan Kaminsky, CISSP
    www.doxpara.com