Re: [Full-Disclosure] ASN.1 telephony critical infrastructure warning - VOIP

[Michal Zalewski <lcamtuf () ghettot org>]

On Tue, 17 Feb 2004, Gadi Evron wrote:

> ASN is what VOIP is based on, and thus the critical infrastructure for
> telephony which is based on VOIP.
>
> This may be a false alarm, but you know how worms find their way into
> every network, private or public. It could (maybe) potentially bring the
> system down.

Balooney. ASN.1 is not a network service, is a notation standard used in,
among other things, some network protocols. A worm that targets one of the
protocols, if is going to show up at all - some disagree with your
assessment the vulnerability is "very easy to exploit", so perhaps it
would be good to substantiate your claim - would not magically start
attacking a wholly different protocol, where ASN.1 is used in a different
way, just like this.

Such a worm would have to target VoIP specifically to attack it
successfully (and this is unlikely, as this is not a vector commonly open
on desktop systems), for starters. Even then, a relatively small
percentage of all VoIP applications, particularly the mission-critical
ones, are running off of Windows, I suppose. The world is not going to end
tomorrow.

That is no say there is no risk; quite the opposite. An aggressive worm
may quite efficiently bring down large parts of critical infrastructure by
simply overloading systems and networks. But then, it would be no
different from Nachi and whatnot, and there's nothing about ASN.1 to it.

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 Michal Zalewski * [http://lcamtuf.coredump.cx]
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--------------------------- 2004-02-17 17:17 --

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