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 (8)
Core 8
Core References
Issue Tracking, Patch, Third Party Advisory x_refsource_misc
https://bugzilla.redhat.com/show_bug.cgi?id=1955695
Mailing List, Patch, Third Party Advisory x_refsource_misc
https://www.openwall.com/lists/oss-security/2021/05/05/5
Patch, Third Party Advisory x_refsource_misc
https://gitlab.com/qemu-project/qemu/-/commit/7ec54f9eb62b5d177e30eb8b1cad795a5f8d8986
Patch, Third Party Advisory x_refsource_misc
https://gitlab.com/qemu-project/qemu/-/commit/05a40b172e4d691371534828078be47e7fff524c
Third Party Advisory x_refsource_confirm
https://security.netapp.com/advisory/ntap-20210708-0008/
Mailing List, Third Party Advisory mailing-list
x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2021/09/msg00000.html
Third Party Advisory vendor-advisory
x_refsource_gentoo
https://security.gentoo.org/glsa/202208-27
Mailing List, Third Party Advisory mailing-list
x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html
Scores
CVSS v3
5.5
EPSS
0.0003
EPSS Percentile
8.1%
Attack Vector
LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Details
CWE
CWE-770
Status
published
Products (4)
debian/debian_linux
9.0
debian/debian_linux
10.0
qemu/qemu
< 6.0.0
redhat/enterprise_linux
8.0 (2 CPE variants)
Published
May 26, 2021
Tracked Since
Feb 18, 2026