OT: security of make as authorized_keys command

Dave Burns tburns at hawaii.edu
Mon Dec 31 01:19:47 UTC 2007


I should probably ask this on an ssh oriented list, but I thought I'd
try my luck here first.

I want to do some remote commands securely. I put a key in my
.ssh/authorized_keys file like so:

command="/usr/bin/make $SSH_ORIGINAL_COMMAND" ssh-rsa AAAAB3NzaC1[etc.etc.]

so I can invoke make targets like so:

ssh username at host target

Assuming the bad guys never get my key, I am fine, even though it is
passwordless.

What if a bad guy does get my key? Then I see three possible problems:

1) somehow use make's -F switch in ssh command to change Makefiles?
2) stack overflow of make or ssh?
3) Somehow put extra command after make target using ';' or something?

And obviously the bad guy can invoke any of the targets in my
makefile, but I've made them pretty innocuous.

So, should I seriously worry about any of these potential problems?
Any other holes I haven't thought of?

The motivation for all this is some cron jobs I want to run, obviously
calls for a passwordless ssh key, but I want to put some limits on it.

Thanks,
Dave




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