- cross-posted to:
- linux@lemmy.ml
- cross-posted to:
- linux@lemmy.ml
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Bit of an alarmist headline here. The vulnerability has been patched in the most common clients (openssh) and it was because the protocol wasn’t being implemented correctly. To say that the SSH protocol “just got a lot weaker” is just not true.
It doesn’t look that simple to me. From the Terrapin paper:
Although we suggest backward-compatible countermea- sures to stop our attacks, we note that the security of the SSH protocol would benefit from a redesign from scratch. This redesign should be guided by all findings and insights from both practical and theoretical security analysis, in a similar manner as was done for TLS 1.3.
It seems the protocol itself needs a revision and implementation-specific patches are easier and less-than-ideal solutions.
One could argue that even these solutions they provide are already changes to the protocol, and not just fixes to implementation bugs. Both the Sequence Number Reset and Full Transcript Hash add or change functionality at the communication protocol level, rather than simply covering corner cases.
Yes I was wrong to say that this an implementation detail rather than a protocol problem as the OpenSSH release notes to prevent this vulnerability include extensions to the SSH Transport Protocol, however I still believe that the headline is sensationalist at best since it can and has been protected against by patching ssh clients and servers. It would be entirely unreasonable in the majority of cases to simply stop using SSH on the basis of this vulnerability and that’s why I think the headline exaggerates the problem. The Register has a much more measured take on this including comments from the paper’s authors that people shouldn’t panic and try to fix immediately.
Yeaaaa, a complete redesign from scratch sounds way more dangerous. “Noah, get the boat” isn’t always the best answer. There’s been a lot of thought and testing put into the magnificent work that is SSH over the past few decades.
I won’t pretend I know better than the paper authors, what I can say is that some fixes are not incremental.
There are cases that mature tools and protocols should be left behind, and the danger lies exactly in using a protocol that was designed in the web 1.0 era.
[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
Well thats easy then, just change your allowed ciphers.
ChaCha20-Poly1305 sounds like an auto-generated Reddit username.
MitM attacks are also one of the major threats to MFA.
They don’t seem to talk much about TLS which is the current standard for most things (VoIP, email.) We still use ssh for a lot but HTTPS is secured through TLS 1.3
