2 ms·
SSHing into an untrusted box is - sadly - a security minefield. Some trip hazards include: -Unless specifically instructed not to, ssh will send all key finger
by dTal 5y ago
SSHing into an untrusted box is - sadly - a security minefield. Some trip hazards include:
-Unless specifically instructed not to, ssh will send all key fingerprints to the server
-ssh sends a string describing the exact version of SSH and operating system you’re running, and this behavior can't be changed
-If the client has taken the unwise but plausibly lazy step of wildcard-enabling ssh agent forwarding, the server can masquerade as the client and log into any servers they have keys for
-If the client has X11 forwarding set up by default, the server can sniff the client's keystrokes (among a great many other things)
- zamadatix 5y agoHaven't heard of the first one before - when you say "all key fingerprints to the server" do you mean the public client key or the public key of the host it's expecting or something else completely? 2 is true is https and most other protocols without concern. The problem usually comes to running an old version not telling the other side you're running an old version. 3/4 seem to only be true if you go and misconfigure settings from defaults, which is true for nearly everything. I'd be curious what the risk of 1 really comes down to because other than that I'm not seeing anything to be worried about if you know you're connecting to an untrustworthy box.
- fiddlerwoaroof 5y ago1 is necessary for ssh keys to work: unless configured otherwise, the client has to send the public key for every private key to the server so the server can determine whether any of the keys is trusted. (a) this isn’t a security issue, but it might be a privacy issue. (b) you can configure ssh to use a specific private key if this really is unacceptable.