Re: SSH brute force blocking tool

On Fri, 01 Dec 2006, J. Oquendo wrote:

> Tonnerre Lombard wrote:
>
>
> >In this case, your awk statement checks that argument $6 is
> >"Illegal" (which it is) and argument $9 is "from" (which it is). So it
> >takes $10 and prints it (in this case, mars.)
> >
> >If you check $10 to look like an IP address, I set my username to
> >"bikermice from 217.14.64.1", you're going to blacklist 217.14.64.1
> >because it is a valid IP.
> >
> > Tonnerre
> >
>
> So again... Some of you guys need to go back and read before you post....

ok, you're right, let's go back and let's read again:

You mention (from the attached mail, you've written):

Nov 27 16:31:21 local sshd[67010]: Illegal user dd from 213.134.128.227
awk '($5=="Illegal"||$6=="Illegal")&&$9=="from"{print $10}'

Note that there is no "NF" in this line.

>
> awk 'NF<=10&&($6=="nvalid"||$7=="user")&&$9=="from"{print $10}'
>

you're fixing your script when someone shows a security hole, that's a
good practice. But don't insult the men who mention the
vulnerabilities... They are actually helping you, because you're improving
your script thanks to them.

>
> Once you try a moronic name insertion it makes the columns more than 10 rows invalidating it.
> Is this a difficult concept to understand? Set your host to whatever you would like, its been
> discussed and resolved. Is there anything else? Perhaps I should re-write TCP into the script
> to ensure no one ever spoofs again.
>

-- 
Raphaël Marichez aka Falco

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