Targeted MitM attacks using information leakage in SSH clients [pdf]

Re:Targeted MitM attacks using information leakage in SSH cl... by tinus_hn on Saturday July 04, 2020 @10:56AM (#23732651)

If you don’t know the host key you are always vulnerable to a man in the middle attack. Is this really a vulnerability in Putty or a design weakness in SSH?

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Re:Targeted MitM attacks using information leakage in SSH cl... by gruez on Saturday July 04, 2020 @02:24PM (#23734000)

It's an intentional design decision. Unlike https, ssh doesn't typically use x509 certificates for authentication, so there's no real way to know whether you're MITM if you're making a connection for the first time.

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Re:Targeted MitM attacks using information leakage in SSH cl... by tptacek on Saturday July 04, 2020 @07:15PM (#23735550)

Modern SSH of course does support certificates --- SSH certificates aren't X.509 --- which solve this problem, the key management problem, and the long-term SSH key hazmat problem. Probably, SSH certificates are what we should have been using all along.

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Re:Targeted MitM attacks using information leakage in SSH cl... by RL_Quine on Saturday July 04, 2020 @04:02PM (#23734553)

SSH supports things like pinning the key in a DNSSEC response.

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