CVE-2021-3527

medium

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.

References

https://www.openwall.com/lists/oss-security/2021/05/05/5

https://gitlab.com/qemu-project/qemu/-/commit/05a40b172e4d691371534828078be47e7fff524c

https://bugzilla.redhat.com/show_bug.cgi?id=1955695

https://gitlab.com/qemu-project/qemu/-/commit/7ec54f9eb62b5d177e30eb8b1cad795a5f8d8986

https://security.netapp.com/advisory/ntap-20210708-0008/

https://lists.debian.org/debian-lts-announce/2021/09/msg00000.html

Details

Source: MITRE

Published: 2021-05-26

Updated: 2021-11-15

Type: CWE-770

Risk Information

CVSS v2

Base Score: 2.1

Vector: AV:L/AC:L/Au:N/C:N/I:N/A:P

Impact Score: 2.9

Exploitability Score: 3.9

Severity: LOW

CVSS v3

Base Score: 5.5

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

Impact Score: 3.6

Exploitability Score: 1.8

Severity: MEDIUM