SANS ISC: TLS Man-in-the-middle on renegotiation vulnerability made public

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TLS 1.0+ and SSL 3.0+  (known from among others "https") is vulnerable to a protocol weakness where a man in the middle could work during the renegotiation phase in modern versions the protocol.

While the details had been offered in a meeting with the IETF, vendors and the open source implementers of SSL privately, it appears an IETF mailing list came to finding it again.  That seems to have prompted the original finders (Marsh Ray and Steve Dispensa) to offer up their finding publicly.

The news media outlets are obviously all over this.

Some links aside of the usual media outlets:

• The original description (site is suffering from a slashdot effect as I write this)
• The summary by the IETF TLS workgroup, and promisses for an amended protocol

There does not seem to be much you can do till the protocol is fixed. The main problem seems to be with clients using certificate authentication.

Exploiting this requires the attacker to be able to intercept the traffic.

Thanks to Martin, Edward, Ken and Chris for sending this in.

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Swa Frantzen -- Section 66