@thisisnotmyname I already covered that (proxying) too: If a malicious program uses port 6263, you would be UNABLE to log into existing sites. The extension would be talking to the fake "1Password mini impersonator" and the impersonator would not have any of your passwords, since it's not the real vault, which in turn means that your extension would be unable to retrieve the passwords of any websites. The real vault would still be locked. THAT is why the paper says "If you log into a NEW site, and tell the extension to SAVE the NEW password, we can intercept it"; because the "save this new password!" request would be sent to the fake 1Password Mini. But it won't affect any of your EXISTING data. As I pointed out in
Post #112, they already designed 1Password with this exact kind of possible impersonation in mind, and your actual vault data is still safe. And you would *quickly* notice that your 1Password extension isn't able to log into any of your pre-existing sites anymore since it's talking to a fake (empty) impersonation vault.
The only way to actually steal *saved* logins is if they either impersonate the whole GUI (not gonna happen, see
post #133), or if they created a proxy that sat between the browser extension and 1Password mini and read all the back/forth communication --
But such a proxy is
impossible to create, since you can't bind multiple apps to the same TCP port, so it's impossible to "sit between" the two apps. That's why this "exploit" has to start *before* the real 1Password Mini, so that it can be the first to bind the port, since you can't have two apps on one TCP port.
The only thing they
could conceivably do is install a packet capture driver (that's a root-level command and would require root access and a restart); which basically means a kernel extension that sits at the TCP/IP stack and observes all network traffic. Such a kernel extension would need to be signed by Apple for it to be loaded by the OS, and they're not going to give out a kernel extension certificate for that.