I just built a gaming PC with a Ryzen 3600. It is more than sufficient to run modern games with demanding graphics and performance. I now need to learn about this exploit. Yes, if someone gets the level of access required to exploit it I was pwned anyway, but now if I get pwned I need to open up my computer and throw away a perfectly powerful CPU, then put it back together with a new one.
That's pretty damn frustrating. It will definitely push me away from AMD when I am making future hardware decision.
EDIT: As pointed out by sqeaky and others, there shouldn't be a method for persistence that lives on the processor, instead it would likely be on the motherboard, or in the bootloader on a storage device.
I don't think there's any indication that the exploit allows the CPU itself to be persistently infected.
> As a matter of fact, the researchers say that the code would likely survive a complete reinstallation of the operating system. The best option for infected computers would be a one-way ticket to the trash heap.
From the Wired article (https://www.wired.com/story/amd-chip-sinkclose-flaw/):
> In fact, for any machine with one of the vulnerable AMD chips, the IOActive researchers warn that an attacker could infect the computer with malware known as a “bootkit” that evades antivirus tools and is potentially invisible to the operating system, while offering a hacker full access to tamper with the machine and surveil its activity. For systems with certain faulty configurations in how a computer maker implemented AMD's security feature known as Platform Secure Boot—which the researchers warn encompasses the large majority of the systems they tested—a malware infection installed via Sinkclose could be harder yet to detect or remediate, they say, surviving even a reinstallation of the operating system.
> Only opening a computer's case, physically connecting directly to a certain portion of its memory chips with a hardware-based programming tool known as SPI Flash programmer and meticulously scouring the memory would allow the malware to be removed, Okupski says. Nissim sums up that worst-case scenario in more practical terms: “You basically have to throw your computer away.”
Do you have differing information?
Consider that even things like CPU microcode don't get stored on the CPU, it's simply doesn't have persistent storage. CPU microcode is often applied early during OS boots and loaded into memory or CPU cache.
What you have quoted indicates something similar, perhaps the main board or other device with storage of some kind is being written to or perhaps an attacker could write a payload that lived entirely in the bootloader on the main storage.
If you can't do that, then this feels significantly less problematic.
> For systems with certain faulty configurations in how a computer maker implemented AMD's security feature known as Platform Secure Boot
Seems like this actually requires two vulnerabilities, then?
Intel CPUs have been self-destructing, so you need to throw away CPUs even if they aren't pwned. They have also had far more security vulnerabilities than AMD, some of them cannot be patched, and operating systems had to work around them. Heck, the Sinkclose name came from 'Sinkhole', which was an Intel vulnerability.
No manufacturer is perfect.