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New AMD SinkClose flaw helps install nearly undetectable malware (www.bleepingcomputer.com)

submitted 3 months ago by [email protected] to c/[email protected]

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AMD is warning about a high-severity CPU vulnerability named SinkClose that impacts multiple generations of its EPYC, Ryzen, and Threadripper processors. The vulnerability allows attackers with Kernel-level (Ring 0) privileges to gain Ring -2 privileges and install malware that becomes nearly undetectable.

Tracked as CVE-2023-31315 and rated of high severity (CVSS score: 7.5), the flaw was discovered by IOActive Enrique Nissim and Krzysztof Okupski, who named privilege elevation attack 'Sinkclose.'

Full details about the attack will be presented by the researchers at tomorrow in a DefCon talk titled "AMD Sinkclose: Universal Ring-2 Privilege Escalation."

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[–] [email protected] 7 points 3 months ago

For everyone who's posting but didn't actually read the CVE...

You need Malware with Kernel level access Already. Besides Anti Cheat for modern games, if you have malware with Kernel level access you're already really fucked.

In addition, this just appears to be a way for that Kernel malware to persist in a device. It's not impossible to detect. I wouldn't be surprised if we saw Windows Defender signatures for malware using it within the month.

I haven't seen the Def Con presentation, but the CVE is a "Maybe". There is no PoC (Proof of Concept, showing that an exploit works)...yet. keep an eye on that.

The CVE claims this "Could Maybe" allow based on logic, but none of the sources i found showed anyone actually using it. Maybe the Def Con presentation will. But unless I see someone post a repeatable exploit in a real world scenario, it feels superficial.

I want to reiterate that this IS a flaw and it IS a problem. But I would highly doubt you, rando consumer, will be affected.

Mitigations are to not be dumb on the Internet. Keep your browser updated and make sure your sensitive data is backed up and encrypted, basic stuff.

Happy to go in to it more. This is my jam.