What’s Vulnerable › Vulnerabilities
CVE-2021-3682
- Severity: high (CVSS 8.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 2.9% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2021-08-05 · updated 2026-06-17
- Weakness: CWE-763
Description
A flaw was found in the USB redirector device emulation of QEMU in versions prior to 6.1.0-rc2. It occurs when dropping packets during a bulk transfer from a SPICE client due to the packet queue being full. A malicious SPICE client could use this flaw to make QEMU call free() with faked heap chunk metadata, resulting in a crash of QEMU or potential code execution with the privileges of the QEMU process on the host.
Affected products
- Debian Linux: 9.0, 10.0, 11.0
- QEMU: before 6.1.0; 6.1.0-rc1 — fixed in 6.1.0
- Red Hat Enterprise Linux: 8.0
How to fix
Upgrade to a fixed version: QEMU 6.1.0. Check the vendor advisory for mitigations.
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1989651
- 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-20210902-0006/
- https://www.debian.org/security/2021/dsa-4980
- https://bugzilla.redhat.com/show_bug.cgi?id=1989651
- 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-20210902-0006/
- https://www.debian.org/security/2021/dsa-4980
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