CVE-2021-3638

Name: CVE-2021-3638
Creator: NVD / NIST
Published: 2022-03-03T23:15:08.147+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 0.43%

Last modified Jun 17, 2026

CVE-2021-3638 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. An out-of-bounds memory access flaw was found in the ATI VGA device emulation of QEMU. This flaw occurs in the ati_2d_blt() routine while handling MMIO write operations when the guest provides invalid values for the destination display parameters. EPSS estimates a 0.43% chance of exploitation in the next 30 days.

Description

An out-of-bounds memory access flaw was found in the ATI VGA device emulation of QEMU. This flaw occurs in the ati_2d_blt() routine while handling MMIO write operations when the guest provides invalid values for the destination display parameters. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

0.43%

34.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Qemu	Qemu	>= 4.0.0, <= 6.1.0
Fedoraproject	Fedora	36
Fedoraproject	Fedora	37

References

https://bugzilla.redhat.com/show_bug.cgi?id=1979858Issue Tracking, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GTVPHLLXJ65BUMFBUUZ35F3J632SLFRK/Mailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7J5IRXJYLELW7D43A75LOWRUE5EU54O/Mailing List, Third Party Advisory
https://lists.nongnu.org/archive/html/qemu-devel/2021-09/msg01682.htmlExploit, Mailing List, Patch, Third Party Advisory
https://security.netapp.com/advisory/ntap-20220407-0003/Third Party Advisory
https://ubuntu.com/security/CVE-2021-3638Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1979858Issue Tracking, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GTVPHLLXJ65BUMFBUUZ35F3J632SLFRK/Mailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7J5IRXJYLELW7D43A75LOWRUE5EU54O/Mailing List, Third Party Advisory
https://lists.nongnu.org/archive/html/qemu-devel/2021-09/msg01682.htmlExploit, Mailing List, Patch, Third Party Advisory
https://security.netapp.com/advisory/ntap-20220407-0003/Third Party Advisory
https://ubuntu.com/security/CVE-2021-3638Third Party Advisory

Timeline

Published: Mar 3, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-3638?

How severe is CVE-2021-3638?

CVE-2021-3638 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.43% probability of exploitation in the next 30 days.

How do I fix CVE-2021-3638?

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-2021-3638?

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

Scan your code now

Source: NVD / NIST