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CTS disclosed several "flaws" in the AMD Ryzen architecture chips. These flaws are called Ryzenfall, Masterkey, Fallout and Chimera (https://amdflaws.com/). However several technology sites (for example Wired) and blogs raised questions as to the motives, release style and severity of the flaws. There also seems to be a very odd disclaimer on the CTS sites. So far it has been hard to find any data without a lot of hype. How severe are these flaws and what do I need to do to secure my systems?

Anders
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AstroDan
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    Probably published by short-sellers. See https://www.servethehome.com/bizarre-amd-epyc-ryzen-vulnerability-disclosure/ – billc.cn Mar 14 '18 at 13:14

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Quotes from the rather detail-free whitepaper:

Exploiting MASTERKEY requires an attacker to be able to re-flash the BIOS with a specially crafted BIOS update.

Exploitable only if you've got the BIOS manufacturer's signing key (if they use one), have written a custom BIOS for the computer being targeted, and (generally) have physical access to the machine.

Exploitation [of RYZENFALL] requires that an attacker be able to run a program with local-machine elevated administrator privileges. Accessing the Secure Processor is done through a vendor supplied driver that is digitally signed.

Exploitation [of FALLOUT] requires that an attacker be able to run a program with local-machine elevated administrator privileges. Accessing the Secure Processor is done through a vendor supplied driver that is digitally signed.

Prerequisites for Exploitation [of CHIMERA]: A program running with local-machine elevated administrator privileges. Access to the device is provided by a driver that is digitally signed by the vendor.

So, at a minimum, you already need full control of the computer and a third party's signing key to exploit these vulnerabilities. Might be useful for a state-level actor trying to install an undetectable keylogger or the like, but the average person isn't at increased risk because of them.

Mark
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