CVE-2021-3750

8.2 HIGH 0.5% exploit odds No fix listed

What it is

A DMA reentrancy issue was found in the USB EHCI controller emulation of QEMU. EHCI does not verify if the Buffer Pointer overlaps with its MMIO region when it transfers the USB packets. Crafted content may be written to the controller's registers and trigger undesirable actions (such as reset) while the device is still transferring packets. This can ultimately lead to a use-after-free issue. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service condition, or potentially execute arbitrary code within the context of the QEMU process on the host. This flaw affects QEMU versions before 7.0.0.

At a glance

Exploitability: Can be exploited locally on the machine with an admin-level account. High risk of data exposure, data tampering, service disruption.
Exploit odds: 0.5% chance of exploitation in the next 30 days (EPSS).
Fix: No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

2021-08-30 00:00 UTC ReservedThe CVE id was reserved by its CNA
2022-05-02 19:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-17 04:05 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.5% in the next 30 days (EPSS).
Severity: 8.2 HIGH (CVSS).
Fix: none linked yet, which raises it.

Details

Published: 2022-05-02 19:15 UTC
Last modified: 2026-06-17 04:05 UTC
Exploit probability: 0.5% · EPSS, next 30 days
Weakness: CWE-416 · Use after free
Record status: Modified

Affected

Qemu < 7.0.0
Redhat Enterprise Linux 8.0

Attack profile CVSS 3.1 · 8.2

Attack vector: Local
Complexity: Low
Privileges needed: High
User interaction: None
Scope: Changed
Confidentiality: High
Integrity: High
Availability: High

Raw vector

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

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-2021-3750.md and follow it. Check whether this project is affected by CVE-2021-3750. 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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References

NVD record · CVE.org record