CVE-2021-3700

Name: CVE-2021-3700
Creator: NVD / NIST
Published: 2022-02-24T19:15:09.26+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.4/10EPSS 0.31%

Last modified Jun 17, 2026

CVE-2021-3700 is a medium-severity vulnerability rated 6.4/10 on the CVSS scale. A use-after-free vulnerability was found in usbredir in versions prior to 0.11.0 in the usbredirparser_serialize() in usbredirparser/usbredirparser.c. This issue occurs when serializing large amounts of buffered write data in the case of a slow or blocked destination.. EPSS estimates a 0.31% chance of exploitation in the next 30 days.

Description

A use-after-free vulnerability was found in usbredir in versions prior to 0.11.0 in the usbredirparser_serialize() in usbredirparser/usbredirparser.c. This issue occurs when serializing large amounts of buffered write data in the case of a slow or blocked destination.

Metrics

CVSS 3.1

6.4/10

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

EPSS Probability

0.31%

22.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Spice-Space	Usbredir	< 0.11.0
Redhat	Enterprise Linux	6.0
Redhat	Enterprise Linux	7.0
Redhat	Enterprise Linux	8.0
Fedoraproject	Fedora	34
Debian	Debian Linux	9.0

References

https://bugzilla.redhat.com/show_bug.cgi?id=1992830Issue Tracking, Patch, Third Party Advisory
https://gitlab.freedesktop.org/spice/usbredir/-/commit/03c519ff5831baPatch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/03/msg00030.htmlMailing List, Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1992830Issue Tracking, Patch, Third Party Advisory
https://gitlab.freedesktop.org/spice/usbredir/-/commit/03c519ff5831baPatch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/03/msg00030.htmlMailing List, Third Party Advisory

Timeline

Published: Feb 24, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-3700?

How severe is CVE-2021-3700?

CVE-2021-3700 has a CVSS score of 6.4/10 (MEDIUM severity). The EPSS model estimates a 0.31% probability of exploitation in the next 30 days.

How do I fix CVE-2021-3700?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-3700?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST