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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-3682
• https://bugzilla.redhat.com/show_bug.cgi?id=1989651
• https://lists.debian.org/debian-lts-announce/2021/09/msg00000.html
• https://security.netapp.com/advisory/ntap-20210902-0006/
• https://www.debian.org/security/2021/dsa-4980
• https://security.gentoo.org/glsa/202208-27
• https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html