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Comment by DrJokepu | Hacker News Reader

I'm no security expert but it was always my understanding is that once an attacker has physical access to a computer it can no longer be considered secure, no matter what. Also, my understanding is that this is a widely accepted fact in the security community. How can a website called "Security Week" ignore this very relevant piece of knowledge then?

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If this is reported correctly, it sounds like passwords are stored in memory for quite a while in their unhashed, clear text form. This is not good for people that depend on FileVault as a way to assume that physical access doesn't necessarily compromise their data.

It's a little hard to believe this as there's really no need to have the password kept in memory; it could be the exploit requires the device to be plugged in while you're typing your password--which is more believable and also less interesting.

If you have the autologin feature enabled, which would you prefer: keep the password in RAM, where most people can't get it, or put it on the hard drive, which is a much easier target?

But why would the autologin implementation need access to the cleartext password ? And then why is the cleartext password stored at all ?

These seems like big holes.

On OSX, probably to unlock keychain.

Yep: http://www.brock-family.org/gavin/perl/kcpassword.html

Mac OS X 10.6 and 10.7 do store clear-text passwords in memory, long after login.

It uses them, too. For convenience's sake (because everything else is locked under other passwords) I use the same usernames/passwords for my local machines, and without prompting me my new Mini was able to access SMB shares on other machines. I'm not terribly worried about it because this password is unique to local logins on my own network, but it was a little unnerving.

If you have full disc encryption enabled, you'll need to keep the encryption key in memory somewhere (encrypted or not). Basically, if an attacker gets hold of your running computer and you don't have serious hardware security then you're screwed.

That's one of those useless truisms, since preventing casual access to a physical attacker is definitely still important.

Do you really think there are security experts who don't bother with screensaver passwords or whole disk encryption?

With proper precautions, systems can be secured properly and with quite good security. Anytime a computer doesn't have encrypted data it's insecure, assuming an attacked has physical access. Installing a new operating system while keeping old data is cake. If a laptop is stolen or attempted to access data that is encrypted with proper security measures, it's pretty tough to break. Nothing is ever 100% secure but with proper security measures and encryption (either full disk or of sensitive data) it's pretty tough.

Nah, if the computer is left on I could use a cold boot attack to dump the memory and find the encryption key in there somewhere. If you really want to secure devices against physical intrusion you'll need to do a bunch of TPM, anti-intrusion, and smartcard work.

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