CVE-2021-3682

Name	CVE-2021-3682
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.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DLA-2753-1, DLA-3099-1, DSA-4980-1
Debian Bugs	991911

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
qemu (PTS)	bullseye	1:5.2+dfsg-11+deb11u3	fixed
	bullseye (security)	1:5.2+dfsg-11+deb11u2	fixed
	bookworm	1:7.2+dfsg-7+deb12u12	fixed
	trixie	1:9.2.0+ds-2	fixed
	sid	1:9.2.0+ds-5	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Origin	Debian Bugs
qemu	source	stretch	1:2.8+dfsg-6+deb9u15	DLA-2753-1
qemu	source	buster	1:3.1+dfsg-8+deb10u9	DLA-3099-1
qemu	source	bullseye	1:5.2+dfsg-11+deb11u1	DSA-4980-1
qemu	source	(unstable)	1:6.0+dfsg-3		991911

Notes

https://gitlab.com/qemu-project/qemu/-/issues/491
Introduced by: https://gitlab.com/qemu-project/qemu/-/commit/b2d1fe67d09d2b6c7da647fbcea6ca0148c206d3 (v1.4.0-rc0)
Fixed by: https://gitlab.com/qemu-project/qemu/-/commit/5e796671e6b8d5de4b0b423dce1b3eba144a92c9 (v6.1.0-rc2)