[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Sneaking past firewalls: ssh on port 23 or 80?



Nunya said on Mon, Dec 15, 2003 at 02:56:06PM -0800:
> I always thought I could have ssh listen on some port which gets through 
> like FTP port or HTTP port to bypass all those restrictions.
> 
> Two obvious, unavoidable problems will be: my employer probably won't 
> want me wasting bandwidth and opening a security hole.
> 
> (1) Will it work and (2) is it opening a security hole?

Ignoring any possible moral issues (ie, why should you be using ssh to your own
server on company time if they have a policy saying you shouldn't)...

1) Yes.  I've done this a few times.  Port 80 can be a bad choice, though; your
sshd will log tons of bad requests from the Windows worm of the week.  OTOH, 80
is the most likely port to be allowed through the firewall.

FWIW, I use ports 25, 80, and 443 for this sort of thing.  ldap, ldaps, imap,
imaps, and pop3 would also be good ports.

2) Depends on what you do with the ssh connection.  Do you open tunnels?  Are
you using it to provide remote access to your workstation?

M

Attachment: pgp3eht0NyZJw.pgp
Description: PGP signature


Reply to: