CVE-2021-20255

Name	CVE-2021-20255
Description	A stack overflow via an infinite recursion vulnerability was found in the eepro100 i8255x device emulator of QEMU. This issue occurs while processing controller commands due to a DMA reentry issue. This flaw allows a guest user or process to consume CPU cycles or crash the QEMU process on the host, resulting in a denial of service. The highest threat from this vulnerability is to system availability.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub advisories/code/issues, web search, more)
References	DLA-2623-1
Debian Bugs	984451

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
qemu (PTS)	buster	1:3.1+dfsg-8+deb10u8	vulnerable
	buster (security)	1:3.1+dfsg-8+deb10u9	vulnerable
	bullseye (security), bullseye	1:5.2+dfsg-11+deb11u2	vulnerable
	bookworm, sid	1:7.1+dfsg-2	vulnerable

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+deb9u14		DLA-2623-1
qemu	source	(unstable)	(unfixed)			984451

Notes

[bullseye] - qemu <postponed> (Minor issue)
[buster] - qemu <postponed> (Minor issue)
https://lists.gnu.org/archive/html/qemu-devel/2021-02/msg06098.html
https://ruhr-uni-bochum.sciebo.de/s/NNWP2GfwzYKeKwE?path=%2Feepro100_stackoverflow1
No upstream patch as of 2022-04-21