CVE-2021-3527

MEDIUM
5.5
CVSS Score
Published: May 26, 2021 at 09:13 PM UTC
Updated: June 17, 2026 at 04:05 AM UTC
3 products affected across 3 vendorsDebian LinuxEnterprise LinuxQEMU

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.4%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

References (8)

x_refsource_MISCIssue TrackingPatchThird Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1955695
Mailing Listx_refsource_MLISTThird Party Advisory
https://lists.debian.org/debian-lts-announce/2021/09/msg00000.html
Mailing Listx_refsource_MLISTThird Party Advisory
https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html
Vendor Advisoryx_refsource_GENTOOThird Party Advisory
https://security.gentoo.org/glsa/202208-27
x_refsource_MISCMailing ListPatchThird Party Advisory
https://www.openwall.com/lists/oss-security/2021/05/05/5

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-770

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