backdoor threat

Bill Moran wmoran at
Fri Jun 19 18:39:37 UTC 2009

In response to prad <prad at>:

> i just received this 'threat' from someone on a forum:

Stay off that forum.  Sounds annoying to me.

> "+1.2507437628 <-- And....,yes of course this is a fax, but I could
> write and execute a script that would have some real fun with it..
> Don't you think. Especially from a BSD server ;)
> You missed a small back door, if you're nice I'll help you close it. ;)"
> i am very curious as to what script this person can write to have fun
> with a fax number. what are they going to do - send me junk faxes
> instead of junk emails?

Sure.  It costs almost nothing to send a fax message, and he could send
it over and over and run you out of paper and ink while you're sleeping.
Infantile, yes.

> however, i'm very curious about the back door. what backdoors are there
> on what is pretty well a freebsd server default setup? i have disabled
> password access. there are some php forms, but i use the proper way to
> set variables. are there other things i should be thinking about?

Sure, there's 1000000000 things.  Start by running a nmap scan from a
different computer and see what ports are open.  Investigate each
program listening on those ports to ensure it's properly secured.

Making secure web forms is too complex to discuss in a single email.

Of course, the "someone" could just be spouting off.  A few years ago,
I had someone claim that they could break into my server because my ports
weren't "stealth" (i.e., because they returned RST packets instead of
just dropping the syns).  I invited the idiot to prove it by breaking in,
which he never accomplished.  Some people brag without being able to back
it up.

Bill Moran

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