Re: PTY DOS vulnerability?

[Paul Rolland]

Hello,

> > second, just providing a user limit doesn't prevent a denial of 
> > service.. Just have more connections than ptys and you are 
> in the same 
> > situation.
> 
> Isn't this something a improved sshd could do?  I.e. if the 
> connection using up the last (or one of the last) pty's logs 
> in as non-root - just kill it.

Why restricting this to SSH ? I mean, this can occur even if you
are not using SSH.

Some per-user limit seems to be good... but if we do that, what about
also limiting the number of TCP/UDP ports used on a per-user basis ?

In fact, all the resources that are available should be per-user limited
if you want to avoid a single one causing a complete DoS...
 - CPU
 - Memory
 - Network
 - Disk
 - Pty
 - ...

Paul