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RE: Future ISAKMP Denial of Service Vulnerablity Needs Addressing



>>>>> "Chris" == Chris Trobridge <CTrobridge@baltimore.com> writes:

 Chris> I've had some thoughts about this.  Consider that rather than
 Chris> generate a 'get out of puzzle free' token that the ISAKMP
 Chris> peers negotiate a shared secret authentication key.
 Chris> Subsequent negotiations could use this key in place of the
 Chris> much more expensive PKI base authentication.  These temporary
 Chris> authentication keys could be cached and wouldn't need to be
 Chris> held for every possible peer.

 Chris> If there's a vulnerability here, then the token could be used
 Chris> to authenticate the initial ISAKMP datagram(s) only and be
 Chris> used in addition to the current authentication mechanisms.

 Chris> This doesn't solve the initial connection issue, but it would
 Chris> help protect established VPNs at rekeying time against attacks
 Chris> on their PK/memory resources.

Interesting notion, but I am worried about the initial connection
aspect as well.  Consider the monday morning effect, or tunnel
re-establishment after a security gateway reboot.

	paul


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