In the case of Spectre, it’s possible to get a CPU to run computer code from a branch it ordinarily would discard. So, some bad computer code is loaded into a system in such a way as it is executed by the processor and then accessed by the attacker who gets can see data that everyone thought was being run in a secure environment. The Red Hat blog says that with Meltdown “the chip is fooled into loading secured data during a speculation window in such a way that it can later be viewed by an unauthorized attacker”. The Spectre and Meltdown vulnerabilities make it possible for someone to either manipulate the results of those different speculative operations (where the processor is guessing what to do next) or see the outcomes of the wrong decisions that are tossed away. Again, processor makers have become really good at guessing what you’ll want when faced with a choice and being ready for the decision. If they guess right – you’re served faster. The barista can serve you faster if they see you before you order and guess which drink you’ll want and start preparing it before you ask. Most days, you order two different drinks either a cappuccino or a hot chocolate. Let’s head to a coffee shop this time – one where the barista knows you reasonably well. Another way to boost processor performance is to guess which way a decision will go ahead of time. You’ll also notice that the descriptions discuss branch prediction. Some of those guesses don’t pan out but CPU makers have become pretty good at predicting what you’re going to do in order to make things faster. Processors do stuff ahead of time, just in case it’s needed, in order to boost performance. Sure, some of the burgers were tossed out but it meant that when you walked into the restaurant that you were served quickly. It’s like when McDonalds used to make burgers ahead of time. This is where a processor carries out a task ahead of it potentially being needed. You’ll notice that all three vulnerabilities talk about a process called speculative execution. Meltdown, or CVE 2017-5754, is similar but allows an attacker to conduct side-channel analysis of the data cache. In this case, CVE 2017-5753 and CVE 2017-5715 are two flaws that have been collectively branded as Spectre.ĬVE 53 are described as “Systems with microprocessors utilizing speculative execution and direct (for 2017-5715 ) and indirect (for 2017-5753) branch prediction may allow unauthorized disclosure of information to an attacker with local user access via a side-channel analysis”. When a vulnerability is reported it’s given a unique identifier so everyone can be are they are talking abut the same thing when discussing a problem. Software vulnerabilities are reported and catalogued in a database called Common Vulnerabilities and Exposures, or CVE. What follows is a plain English guide to Spectre and Meltdown.Īlthough there are two names out there, Spectre and Meltdown, we are actually dealing with three different vulnerabilities in computer processors. And while many people are aware that these vulnerabilities exist and that tech companies are doing their best to plug the leaky bits of code, many aren’t really clear on what the problems are. Spectre and Meltdown are the collective names for three different vulnerabilities found in the processors powering a vast number of the computing devices we rely on, from desktop and notebook PCs through to smartphones and other gadgets.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |