CSCI6268L36 - Foundations of Network and Computer Security...

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Foundations of Network and Foundations of Network and Computer Security Computer Security J J ohn Black Lecture #35 Dec 9 th 2009 CSCI 6268/TLEN 5550, Fall 2009
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More Contemporary Problems in Network Security So WEP is the only wide-spread and officially- recognized security protocol in the 802.11 standard, and it is awful There is WPA and WPA2 – not implemented everywhere But wait there’s more: Several other long-standing protocols are also badly flawed; today we’ll look at two more ARP DNS
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ARP: Address Resolution Protocol We already went through this protocol at a high level: ARP_REQUEST ARP_REPLY Passive caching Easily Spoofed Note: this is for LANs only
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ARP Packet Hardware Type 1 = Ethernet; ProtocolType 0x0800 = IP; Operation 1 = Request, 2 = Reply; Source MAC and IP, then Target MAC and IP follow
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ARP Cache Poisoning Client A requests MAC for IP 1.1.1.1 Client B replies “I am 1.1.1.1 with MAC 01:01:01:01:01:01” (broadcast) Client C hears reply and caches 1.1.1.1 01:01:01:01:01:01 Unsolicited replies are also cached Suppose gateway IP is 10.10.10.10 and A’s IP is 2.2.2.2 B tells A: 10.10.10.10 01:01:01:01:01:01 B tells gateway: 2.2.2.2 01:01:01:01:01:01 Note: these are unicast ARP_REPLYs
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Man-in-the-Middle A Gateway B (MAC: 01:01:01:01:01:01) B now proxies all traffic between A and the outside world
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This note was uploaded on 03/11/2010 for the course CS 6268 taught by Professor Black during the Spring '09 term at University of Colombo.

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CSCI6268L36 - Foundations of Network and Computer Security...

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