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Cold Boot Attacks

blog.f-secure.com

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Re: Cold Boot Attacks

#31

Post by pjc50 »

simias wrote: post #22
pjc50 wrote: post #10

Everyone's quickly jumping in to post "physical access is not secure", while over there Apple have iPhones that appear to be almost completely secure against all but the most dedicated state-level attacks (and of course compromised accounts). We can do better, and should. Without compromising the freedom to change operating system. Mind you we also need to keep pressing on security for the desktop, against ransomware…

There are so many easier way to compromise the computers of 99% of the population that this particular flaw, while interesting, doesn't really appear all that critical to me. How many people (or even companies) bother to encrypt their hard drives these days? Not many in my experience. And for those who do how hard will it be to phish the credentials using basic social engineering? If you're carrying nuclear codes the…

> If you're security officer for a small company then you probably have a long list of things to worry about before you have to consider cold boot vulnerabilities.

Do you have laptops? Do you keep any personal data on them? Are you subject to GDPR? Then you do need to worry at least somewhat: https://www.databreachtoday.com/data-breach-another-stolen-l...

Re: Cold Boot Attacks

#32

Post by hannasanarion »

hyperpape wrote: post #21
hannasanarion wrote: post #14

Earlier quoted context omitted.

IPhones are probably vulnerable to cold boot too. It's just that cold boot attacks are absurdly difficult to execute. They only work if you already have physical access to an unlocked device before it powers down. If you shut off your machine and wait two seconds before walking away, you can never be cold-booted

Are you sure/can you provide sources? Given the substantial efforts law enforcement has been taking to get access to suspects' iPhones, this doesn't seem right.

I think you misread me. IPhones are almost certainly vulnerable to some kind of cold-boot attack, yes. That doesn't mean that it's easy to break into them. Cold-boot attacks are highly circumstantial.

If the San Bernadino terrorists shut down their phones before their murderous rampage, or if they ran out of battery before the FBI got into their house, sorry, no cold boot for you.

Cold boot only works if you have physical access to the unlocked, powered-on, in-use device. The "data ghost" in memory that cold boot attacks take advantage of is only there for seconds.

Re: Cold Boot Attacks

#33

Post by hyperpape »

albntomat0 wrote: post #26
hyperpape wrote: post #21

Earlier quoted context omitted.

Are you sure/can you provide sources? Given the substantial efforts law enforcement has been taking to get access to suspects' iPhones, this doesn't seem right.

The commenter above specifically says powered on, unlocked. If the phone is locked or powered off, things are much harder.

I guess I was confused by "If you shut off your machine", which is not the same thing as locking it.

If cold boot attacks only work against unlocked devices, that makes a lot of sense. But if they work against locked but powered devices, that would be quite possible for LE to exploit in most cases (just carry a battery pack).

Re: Cold Boot Attacks

#34

Post by liftbigweights »

arcticbull wrote: post #28
liftbigweights wrote: post #4

That's why the #1 rule of security is physical security. If someone has physical access to your computer, it's pretty much game over.

Tell that to the FBI trying to get into an iPhone

They succeeded...

https://money.cnn.com/2016/03/28/news/companies/fbi-apple-ip...

Re: Cold Boot Attacks

#35

Post by jarfil »

bardworx wrote: post #2

From a security standpoint, isn’t there a common understanding that if an attacker gains physical access to your computer, you already lost? As a side note, there are so many vulnerabilities constantly coming out that I’ve almost became desensitized. I’m sure that’s not a good thing but it’s almost like “when” not “if” someone will just steal my data. Not sure if anyone agrees or I’m just a one-off...

Some parts of a computer are easier to access than others. Like, it's quite easy to access the contents of a hard drive, but not so much some value stored in a particular register in the CPU. That's why it makes sense to encrypt data stored on a hard drive, but we expect the CPU to be able to handle plaintext securely.

Turns out, we should think of RAM more like a hard drive than like something internal to the CPU.

Re: Cold Boot Attacks

#36

Post by 21 »

simias wrote: post #27
jarfil wrote: post #17

So when are we getting encrypted RAM? With all the talk I hear about "cache being the new RAM", since it's so much faster, particularly the L1, it sounds like it would make sense to have some transparent encryption going on. A random key generated at power on, then kept inside the CPU, and instantly lost at power off, would be enough to secure the contents of DIMMs against attacks like this.

Somebody could put a hardware keylogger on your keyboard interface instead. Or de-solder your CPU and replace it with a backdoored version.

Seriously?

How many backdoored CPU attacks have you heard of before?

If you need protection against that, might as well live inside a vault.

Re: Cold Boot Attacks

#37

Post by acura »

jo909 wrote: post #23
acura wrote: post #6

Cold boot, you keep using this word and you don't know what it means. Or is it me who have a screwed definiton of cold boot?

As defined in the article: "when a computer is reset without following proper procedures (what’s known as a cold/hard reboot)" Even if you disagree, "cold boot attack" is the established name for the actual attack, the new aspect presented here is how to circumvent a certain firmware protection that would overwrite the memory on a cold boot to prevent that attack. If you would give your definition we could see if it…

I thought the definition of cold boot was a boot from a powered down state.

Re: Cold Boot Attacks

#38

Post by kilo_bravo_3 »

pjc50 wrote: post #10

Everyone's quickly jumping in to post "physical access is not secure", while over there Apple have iPhones that appear to be almost completely secure against all but the most dedicated state-level attacks (and of course compromised accounts). We can do better, and should. Without compromising the freedom to change operating system. Mind you we also need to keep pressing on security for the desktop, against ransomware…

>Without compromising the freedom to change operating system.

Privacy, freedom, and security advocates seem to have opposing and wholly incompatible goals when it comes to technology.

This attack is possible because the NVRAM is overwriteable.

In order to mitigate this attack, you a manufacturer would need to make NVRAM non-NV or add an security device like Apple's T2 chip. Or encrypt the NVRAM and (to prevent a key management nightmare brought about by having millions of users) keep the keys private, in which case all of the haxxors would be crying "they're locking us out of our own hardware!"

But adding a security device attacks "freedom".

    10 PRINT "Having the vulnerability is bad."
    20 PRINT "But adding security attacks freedom."
    30 GOTO 10
If all of these raging against the machine Zer0cools were highly paid security consultants in 1981 looking to stir up business by raging against some machines, they would have pilloried IBM for implementing their (pre) ISA bus and Commodore for allowing users to PEEK and POKE into random memory addresses. The former created the entire personal computing marketplace as we know it today, and the latter enabled millions of programmers to understand their machines and make them do things the designers never could have imagined.

There was a HN article a while ago about how manufacturers were dumb and we were all going to die because of Thunderbolt and PCIe security flaws where attackers could sniff traffic on the bus.

I was just like "no shit, you've been able to do that forever, that's the point of busses and locking them down will just speed the Applefication of computing".

Back in "THE GOOD OLD DAYS" when men were men and computers were free and open they had god damned card-edge connectors sticking out of the back of the case which gave anyone within arms reach of the machine direct and unrestricted access to the CPU lines.

You cannot have closed openness.

Re: Cold Boot Attacks

#39

Post by comboy »

arachnids wrote: post #7
leejoramo wrote: post #5

physical access = compromised system There are things you can do to mitigate this problem, but once someone has physical access to a computer they have many pathways to gaining access to data and control.

This is already not true for modern iPhones. I think the time to stop accepting this has come. We should demand better from commodity devices.

I think most disagreement in this thread comes from not separating two very different cases.

1) I got access to you hardware and I want to extract data from it

2) I got access to your hardware and I get to give it back to you and you continue using it as if nothing happened

Re: Cold Boot Attacks

#40

Post by 21 »

hannasanarion wrote: post #13

So do y'all regularly dump liquid nitrogen on your computers after powering them off? Last I checked, cold boot attacks have to be executed within moments of a computer powering down unless it's immediately put on ice. I don't understand why we're worried about this.

Read the article. This is about attacking computers in sleep mode.
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