[CentOS] Centos VPS Kernel 2.6.35.4 & 'string-less' IP tables

[Always Learning]

On Wed, 2011-08-31 at 08:41 -0700, John R Pierce wrote:

> On 08/31/11 8:22 AM, Always Learning wrote:
> > Looking at your example seems to suggest Fail2Ban is an 'after the
> > event' response. I would like to implement 'before the event' filtering
> > which prevents, even on the first detected hacking attempt, anything
> > reaching HTTPD.

> so you want another piece of software to parse the http protocol and 
> analyze the traffic, before passing it on to your web server, which is 
> going to parse the http protocol and deliver content?  good luck with that.

No I do not want "another piece of software to parse the http protocol
and analyze the traffic".

IT Tables, in which I have great confidence and trust, can do it.

Thank you for your 'good luck' wishes.

> of course, to even consider doing such you would have to, in very 
> precise terms, define exactly what comprises a 'hacking attempt'.   do 
> you give this filter a list of all valid URLs and trigger your block on 
> any that aren't on that list?

My definition: a hacking attempt is deliberately, meaning not a typing
error, sending an invalid web page request. Obviously one should exclude
the 'standard' wrong URLs issued by some software like the M$ Office
responses and crossdomain requests.

Inspection in IP Tables is performed before the data is passed to HTTPD.
Therefore it is impossible to determine, at that point in the
transmission process, the validity of incoming HTTP requests. Only HTTPD
can decide that issue.

> anyways, the design of such would better be discussed on a security 
> tools mail list as its a very general topic, there's nothing here even 
> remotely centos specific.

IP Tables is and Centos Ops or Sys Admins or others may wish to deploy
the IP Tables blocking suggestion.


Paul.