CVE-2022-42336

What it is

Mishandling of guest SSBD selection on AMD hardware The current logic to set SSBD on AMD Family 17h and Hygon Family 18h processors requires that the setting of SSBD is coordinated at a core level, as the setting is shared between threads. Logic was introduced to keep track of how many threads require SSBD active in order to coordinate it, such logic relies on using a per-core counter of threads that have SSBD active. When running on the mentioned hardware, it's possible for a guest to under or overflow the thread counter, because each write to VIRT_SPEC_CTRL.SSBD by the guest gets propagated to the helper that does the per-core active accounting. Underflowing the counter causes the value to get saturated, and thus attempts for guests running on the same core to set SSBD won't have effect because the hypervisor assumes it's already active.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. Limited direct impact.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2023-05-17 01:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 05:04 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.3% in the next 30 days (EPSS).
• Severity: 3.3 LOW (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2023-05-17 01:15 UTC

Last modified

2026-06-17 05:04 UTC

Exploit probability

0.3% · EPSS, next 30 days

Record status

Modified

Affected

• Xen 4.17

Attack profile CVSS 3.1 · 3.3

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2022-42336.md and follow it. Check whether this project is affected by CVE-2022-42336. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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