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blackhat conference usa 2003 blackhat 23 downgrade

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Unformatted text preview: ce - USA 2003 Blackhat 23 Downgrade Attacks L2TP rollback L2TP can use IPSec ESP as transport layer (stronger L2TP than PPTP) By default L2TP is tried before PPTP By Blocking ISAKMP packets results in an IPSec failure Blocking Client starts a request for a PPTP tunnel (rollback) Client Now you can perform PPTP previous attacks Now Blackhat Conference - USA 2003 Blackhat 24 PPTP Attack DEMO Blackhat Conference - USA 2003 Blackhat 25 MITM attacks Different attacks in different scenarios: scenarios: LOCAL AREA NETWORK: - ARP poisoning - DNS spoofing - Port stealing - STP mangling FROM LOCAL TO REMOTE (through a gateway): - ARP poisoning - DNS spoofing - ICMP redirection - IRDP spoofing - DHCP spoofing - route mangling REMOTE: - DNS poisoning - route mangling - traffic tunneling WIRELESS: - Access Point Reassociation Blackhat Conference - USA 2003 Blackhat 26 MITM attacks ARP poisoning ARP is stateless (we all knows how it works and what ARP the problems are) Some operating systems do not update an entry if it is Some not already in the cache, others accept only the first received reply (e.g solaris) The attacker can forge a spoofed ICMP packets to force The the host to make an ARP request. Immediately after the ICMP it sends the fake ARP replay Usefull on switched lan (the switch will not notice the Usefull attack) Blackhat Conference - USA 2003 Blackhat 27 MITM attacks ARP poisoning - countermeasures countermeasures YES - passive monitoring (arpwatch) YES YES - active monitoring (ettercap) YES YES - IDS (detect but not avoid) YES YES - Static ARP entries (avoid it) YES YES - Secure-ARP (public key auth) YES NO - Port security on the switch NO NO - anticap, antidote, middleware approach NO Blackhat Conference - USA 2003 Blackhat 28 ARP Poisoning DEMO (all we have done until now …) Blackhat Conference - USA 2003 Blackhat 29 ARP Poisoning Antidote Kernel Patch http://www. securityfocus.com/archive/1/299929 http...
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This document was uploaded on 03/17/2014 for the course CS 393 at NYU Poly.

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