CVE-2021-20181

Name	CVE-2021-20181
Description	A race condition flaw was found in the 9pfs server implementation of QEMU up to and including 5.2.0. This flaw allows a malicious 9p client to cause a use-after-free error, potentially escalating their privileges on the system. The highest threat from this vulnerability is to confidentiality, integrity as well as system availability.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub code/issues, web search, more)
References	DLA-2560-1
NVD severity	medium

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
qemu (PTS)	stretch	1:2.8+dfsg-6+deb9u9	vulnerable
	stretch (security)	1:2.8+dfsg-6+deb9u16	fixed
	buster, buster (security)	1:3.1+dfsg-8+deb10u8	vulnerable
	bullseye	1:5.2+dfsg-11	fixed
	bullseye (security)	1:5.2+dfsg-11+deb11u1	fixed
	bookworm	1:6.1+dfsg-6	fixed
	sid	1:6.1+dfsg-7	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
qemu	source	stretch	1:2.8+dfsg-6+deb9u13		DLA-2560-1
qemu	source	(unstable)	1:5.2+dfsg-4

[buster] - qemu <postponed> (Minor issue)
https://git.qemu.org/?p=qemu.git;a=commit;h=89fbea8737e8f7b954745a1ffc4238d377055305