CVE-2021-3527
qemu - security update
5.5
MEDIUM
CVSS 3.1
EPSS 0.08%
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.
How to fix CVE-2021-3527
To remediate CVE-2021-3527, upgrade the affected package to a fixed version below.
- —upgrade to 1:5.2+dfsg-11 or later
- —upgrade to 1:2.8+dfsg-6+deb9u15 or later
Is CVE-2021-3527 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 1:5.2+dfsg-11
- from 0, < 1:2.8+dfsg-6+deb9u15
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |