bugtraq August 2007 archive
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bugtraq: Re: Skype Network Remote DoS Exploit

Re: Skype Network Remote DoS Exploit

From: Valery Marchuk <tecklord_at_nospam>
Date: Tue Aug 21 2007 - 01:52:23 GMT
To: "Steven M. Christey" <coley@mitre.org>, <bugtraq@securityfocus.com>

Skype made a funny "explanation" of the problem...

Lets say, people download updates on Tuesday in the US, on Wednesday in Europe and just happen to reboot their computers simultaneously on Thursday? :)

As I remember, there were two primary theories of the problem source:

  1.. Microsoft's updates
  2.. DoS attack
It seems Skype has decided to make their own theory based on these two: so it was a DoS, but not an attack, and it was updates fault, but not Microsoft's.

I do believe that the DoS Exploit, published at www.securitylab.ru, might have such an impact, but it's impossible to prove anything and it's not necessary. I just would like to say, that Skype could came up with more realistic story, for example: someone made a mistake in the code, or they were trying to implement new feature and everyone would believe, even me :)

Best regards,

Valery Marchuk


  • Original Message ----- From: "Steven M. Christey" <coley@mitre.org> To: <tecklord@argocom.cv.ua>; <bugtraq@securityfocus.com> Sent: Monday, August 20, 2007 8:39 PM Subject: Re: Skype Network Remote DoS Exploit

> The outage being experienced by Skype was apparently due to massive
> simultaneous reboots and reconnects after systems installed their
> Windows patches.
> from http://heartbeat.skype.com/2007/08/what_happened_on_august_16.html:
> The disruption was triggered by a massive restart of our users'
> computers across the globe within a very short timeframe as they
> re-booted after receiving a routine set of patches through Windows
> Update.
> The high number of restarts affected Skype's network resources.
> This caused a flood of log-in requests, which, combined with the
> lack of peer-to-peer network resources, prompted a chain reaction
> that had a critical impact.
> I wonder how many other services are impacted by simultaneous Windows
> scheduled updates.
> Anyway... given that this was going on at the time the SecurityLab.ru
> exploit was released, and the exploit only claims a DoS (and only
> seems to make a series of requests to long URIs), was the exploit
> actually effective, or was the "DoS" just part of the larger outage?
> - Steve