CVE Database›Document archive›CVE-2021-3750

CVE-2021-3750

QEMU: hcd-ehci: DMA reentrancy issue leads to use-after-free

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Severity

Moderate

Red Hat Product Security

7.5

CVSS 3.1

Review impact separately from score.

Published · August 26, 2020

Updated · June 28, 2026

Description

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.

Statement

This CVE is rated as having a Moderate security impact on Red Hat Enterprise Linux. For additional details, refer to https://bugzilla.redhat.com/show_bug.cgi?id=1999073#c5.

CVSS score applicability

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

CVSS / CWE

CVSS 3.1 · 7.5
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H

CWE-416 · Use After Free