CVE-2021-3527

QEMU: usb: unbounded stack allocation in usbredir

Published May 26, 2021 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
A flaw was found in the USB redirector device (usb-redir) of QEMU. Small USB packets are combined into a single, large transfer request, to reduce the overhead and improve performance. The combined size of the bulk transfer is used to dynamically allocate a variable length array (VLA) on the stack without proper validation. Since the total size is not bounded, a malicious guest could use this flaw to influence the array length and cause the QEMU process to perform an excessive allocation on the stack, resulting in a denial of service.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-2753-1 qemu security update
Debian DLA Debian DLA DLA-3099-1 qemu security update
EUVD EUVD EUVD-2021-26843 A flaw was found in the USB redirector device (usb-redir) of QEMU. Small USB packets are combined into a single, large transfer request, to reduce the overhead and improve performance. The combined size of the bulk transfer is used to dynamically allocate a variable length array (VLA) on the stack without proper validation. Since the total size is not bounded, a malicious guest could use this flaw to influence the array length and cause the QEMU process to perform an excessive allocation on the stack, resulting in a denial of service.
Ubuntu USN Ubuntu USN USN-5010-1 QEMU vulnerabilities
Ubuntu USN Ubuntu USN USN-8412-1 QEMU vulnerabilities
History

No history.

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Aug 3, 2024, 5:01 PM
Reserved
Apr 30, 2021, 12:00 AM
Status
Modified
Published
May 26, 2021, 10:15 PM
Modified
Jun 17, 2026, 4:05 AM
Severity
Low
Public date
Apr 30, 2021, 12:00 AM