On Thu, 2009-08-06 at 13:47 +0100, Keith Gearty wrote:
> Scott Lawrence wrote:
> 
> >As long as any call to the PSTN requires some permission, an attacker
> >needs to be able to guess the password of a user with that permission.
> >
> Out of interest, is there any brute-force detection & lock-out in SipXecs?

No - the basic problem with such things is that they are a built-in
denial of service attack.  

Peter Selc adds:

> A mechanism, where sipxecs can detect, that extension XYZ  tries to
> register 1000x times in 1minute -> it can be a brute force attack -> i
> will block this IP and this XYZ extension for 1hour even if
> credentials
> are OK.

So all I need to kill your account is your phone number - I don't need
your password, I just need to deliberately fail to register by using a
known bad password (very easy to guess :-) ).  In a few seconds, I can
disable your account so that _you_ can't register.

As a point of interest - we see these streams of very fast registration
attempts pretty frequently when someone connects a buggy phone to the
network, so the tool to implement those DoS attacks already exists.


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