CVE-2021-3713

Severity: high (CVSS 7.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-08-25 · updated 2026-06-17
Weakness: CWE-787

Description

An out-of-bounds write flaw was found in the UAS (USB Attached SCSI) device emulation of QEMU in versions prior to 6.2.0-rc0. The device uses the guest supplied stream number unchecked, which can lead to out-of-bounds access to the UASDevice->data3 and UASDevice->status3 fields. A malicious guest user could use this flaw to crash QEMU or potentially achieve code execution with the privileges of the QEMU process on the host.

Affected products

Debian Linux: 9.0, 10.0, 11.0
QEMU: through 6.1.0

References

https://bugzilla.redhat.com/show_bug.cgi?id=1994640
https://lists.debian.org/debian-lts-announce/2021/09/msg00000.html
https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html
https://security.gentoo.org/glsa/202208-27
https://security.netapp.com/advisory/ntap-20210923-0006/
https://www.debian.org/security/2021/dsa-4980
https://bugzilla.redhat.com/show_bug.cgi?id=1994640
https://lists.debian.org/debian-lts-announce/2021/09/msg00000.html
https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html
https://security.gentoo.org/glsa/202208-27
https://security.netapp.com/advisory/ntap-20210923-0006/
https://www.debian.org/security/2021/dsa-4980

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