CVE-2021-3638

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2022-03-03 · updated 2026-06-17
Weakness: CWE-787

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.

Affected products

Fedoraproject Fedora: 36, 37
QEMU: from 4.0.0 through 6.1.0

References

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

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