Wifi Security

Steven M. Bellovin smb at cs.columbia.edu
Mon Nov 21 15:27:38 UTC 2005


In message <73345C98-EB2D-4DB5-A8BD-D23D77A51E49 at ianai.net>, "Patrick W. Gilmor
e" writes:
>
>On Nov 21, 2005, at 9:42 AM, Ross Hosman wrote:
>
>> So my question is pretty simple. You have all these major companies  
>> such
>> as google/earthlink/sprint/etc. building wifi networks. Lets say I  
>> want
>> to collect peoples information so I setup an AP with the same ssid as
>> google's ap so people connect to it and I log all of their traffic.  
>> Most
>> people won't check beyond the ssid to look at the mac address but even
>> that could be spoofed. Is there anyway to verify a certain ap beyond
>> mac/ssid, will there be in the future? How do these companies plan to
>> mitigate this threat or are they just going to hope consumers are  
>> smart
>> enough to figure it out?
>
>Why would you even need to set up an AP?  Why not just sit and sniff  
>traffic?  Gets you the _exact_ same information.
>
>And why worry about Google, etc., when Starbucks and airports have  
>been doing this for _years_?
>
>Lastly, most consumers are smart enough to know to use encryption  
>(the little pad-lock in their browser).  Some aren't.  Changing the  
>WiFi architecture is not going to save those who aren't.

By setting up a fake AP, you can launch active attacks.  Sure, people 
won't get the right certificate -- and they're not going to notice, 
especially if the (unencrypted) initial web splash page says something 
like "For added security, all SSL connections from this hotspot will 
use Starbucks-brand certificates.  Please configure your browser to 
accept them -- it will protect you from fraud."

		--Steven M. Bellovin, http://www.cs.columbia.edu/~smb





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