For Terrapin to be viable, the connection it interferes with also must be secured by either “ChaCha20-Poly1305” or “CBC with Encrypt-then-MAC,” both of which are cipher modes added to the SSH protocol (in 2013 and 2012, respectively). A scan performed by the researchers found that 77 percent of SSH servers exposed to the Internet support at least one of the vulnerable encryption modes, while 57 percent of them list a vulnerable encryption mode as the preferred choice.
Also that in order to exploit this it requires an active man in the middle. Which requires any of the following:
Reverse proxy hijack/NAT hijack - from a compromised machine near the server
BGP hijack - stealing traffic to the real IP
DNS hijack - stealing traffic to send to a different IP
Malicious/compromised network transit
Local network gateway control
WAP poisoning - wifi roaming is designed really well so this is actually easier than it sounds.
Almost all of those have decent mitigations like 801.x and BGP monitoring. The best mitigation is that you can just change your client config to disable those ciphersuites though.
you missed this part:
Also that in order to exploit this it requires an active man in the middle. Which requires any of the following:
Almost all of those have decent mitigations like 801.x and BGP monitoring. The best mitigation is that you can just change your client config to disable those ciphersuites though.