nanog mailing list archives

Re: Wifi Security


From: "Stephen J. Wilcox" <steve () telecomplete co uk>
Date: Mon, 21 Nov 2005 23:29:03 +0000 (GMT)


On Mon, 21 Nov 2005, Joel Jaeggli wrote:

On Mon, 21 Nov 2005, Stephen J. Wilcox wrote:

<snip>

What do you learn by looking at someone's ipsec, ssl-wrappered, or ssh
tunneled traffic?

no, we're not trying to do that, you dont really think that because its
encrypted it cant be decrypted do you?

I do believe (reasonably so, I think) that if I'm going have a conversation
with a second party whom I already trust, that a third party will have trouble
inserting themself into the path of that conversation without revealing their
presence..

this is assuming that you are talking to the second party and not in fact me 
sitting in the middle grabbing credentials, possibly by this stage already 
pretending to be that second party

its also assuming you understand your certificates, keys and trust. i'd bet most
users will click yes when presented with a 'do you trust this new key' message.

you dont have to break the code if the endpoints trust sessions with you and
share their encryption keys

Successfully inserting yourself in the middle requires some social-engineering
or really bad protocol design. The former can be mitigated through vigilance,
the later falls into the realm of peer review and security research.

you forgot to include 'or user error'.. the protocol may be fantastic but if the 
user fails to notice a security alert or does something stupid it can be 
compromised. 

depending on how good you are you may be able to thwart all but the determined
hacker, altho to be fair most people are not going to be a target once they
employ basic security such as weak encryption. but if you are a target then its 
vital to be using strong trusted secuity and know your onions!

If I may paraphrase the original posters question (Ross Hosman), it was:

Do large wireless buildouts present a new security threat due to the potential
to spoof AP's?

The answer to that is no, this is a threat we live with currently. We have 
tools to mitigate the risks associated with it.

mmmmmm.. i'd say yes. wifi is still pretty niche, its in the offices, its in 
airports and starbucks. 

once billy bob and his grandpa start using it tho you're bringing it to the 
masses who arent IT trained, who havent had a security brief, who are running 
windows thats not been patched for 2 years and who think 'billy' is reasonable 
for their password

so the technology is the same, but the users are new

You can say that consumers are stupid, and won't figure this out, 

okay "consumers are stupid, and won't figure this out" :-)

and that may be true; however when it's starts to cost them losts money, they
will sit-up take notice and buy tools to solve this problem for them, just
like they do with any other security threat that goes beyond being an
anoyance.  probably said product will be blue, say linksys on it, and have the
word vpn (among others) buried on the packaging someplace.

i'm thinking beyond your corporate staff who are currently using these systems
(and quite badly if my casual network sniffing in environments with supposedly
clued individuals is anything to go by!) 

my 2-cents :0)

Steve


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