RE: Cisco vulnerability and dangerous filtering techniques

["Austad, Jay" <JAustad () temgweb com>]

I was thinking about this the other day.  The most efficient way to make
this work would be to spread using some vulnerability (like the Microsoft
DCOM vulnerability released last week), and then at a predetermined time,
start DoS'ing routers in the IP space of major providers, and then work your
way towards the "edges."  You can pretty much safely assume that most of
your infected machines are going to basically be on the edges of the
internet, so if you start with major providers, you won't kill all of your
connectivity.  Even more destructive would be p2p built into it, so all of
the infected hosts could coordinate before the attack on what networks each
one would handle.

Someone is likely going to attempt something similar, it's just a matter of
time before it happens.  Luckily this Cisco problem didn't come out around
the same time as the slammer worm.

Jay

> -----Original Message-----
> From: jgraun () comcast net [mailto:jgraun () comcast net]
> Sent: Tuesday, July 22, 2003 9:58 AM
> To: Adam Maloney
> Cc: nanog () merit edu
> Subject: Re: Cisco vulnerability and dangerous filtering techniques
>
>
>
> That is a bit paranoid, but it could happen.  I have not seen 
> anybody do 
> anything that intelligent in the past couple of years.  Not 
> to say that there 
> arent people out there that couldn't do that but I think many 
> have thought of 
> using one exploit to expose another, DDoS is the closest I 
> have seen on any of 
> my honeypots.  I have learned many things about what most 
> people will try to 
> get into a box from the honeypots, but that is a good point.  
> Filtering or 
> patching should take place on the edge and on the most 
> critical spots on your 
> network.
>
> Good Luck
> > I had a passing thought over the weekend regarding Thursday's cisco
> > vulnerability and the recent Microsoft holes.
> >
> > The next worm taking advantage of the latest Windows' 
> vulnerabilities is
> > more or less inevitable.  Someone somewhere has to be 
> writing it.  So why
> > not include the cisco exploit in the worm payload?
> >
> > Based on past history, there will be plenty of vulnerable 
> Windows hosts to
> > infect with the worm.  I would also guess that there are lots of
> > organizations and end-users that have cisco devices that 
> haven't patched
> > their IOS.  Furthermore, I wonder how many people have 
> applied filtering
> > only at their border?  But packets from an infected host inside the
> > network wouldn't be stopped by filtering applied only to 
> the external
> > side.
> >
> > Basically, if you're filtering access to your interface 
> IP's rather than
> > upgrading IOS, remember that the internet isn't the only 
> source of danger
> > to your network.
> >
> > Adam Maloney
> > Systems Administrator
> > Sihope Communications