Vulnerability identifier: #VU63684

Vulnerability risk: Medium

CVSSv3.1: 6.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-26339

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
3rd Gen AMD EPYC Processors
Hardware solutions / Firmware

Vendor:

Description

The vulnerability allows a remote user to perform a denial of service (DoS) attack.

The vulnerability exists due to an error in the AMD CPU’s core logic when using specific code from an unprivileged VM. A remote user with low-privileged access to guest OS can send a specific x86 instruction sequence that triggers CPU core hang.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

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External links
http://www.amd.com/en/corporate/product-security/bulletin/amd-sb-1028

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.