5 ms·
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?
by tinus_hn 6y ago
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?
- gruez 6y agoIt'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.
- RL_Quine 6y agoSSH supports things like pinning the key in a DNSSEC response.
- tptacek 6y agoModern 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.