CVE-2021-20177

Name	CVE-2021-20177
Description	A flaw was found in the Linux kernel's implementation of string matching within a packet. A privileged user (with root or CAP_NET_ADMIN) when inserting iptables rules could insert a rule which can panic the system. Kernel before kernel 5.5-rc1 is affected.
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-2557-1, DSA-4843-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	buster	4.19.249-2	fixed
	buster (security)	4.19.269-1	fixed
	bullseye	5.10.158-2	fixed
	bullseye (security)	5.10.162-1	fixed
	bookworm, sid	6.1.20-1	fixed

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

Package	Type	Release	Fixed Version	Origin
linux	source	stretch	(not affected)
linux	source	buster	4.19.171-2	DSA-4843-1
linux	source	(unstable)	5.5.13-1
linux-4.19	source	stretch	4.19.171-2~deb9u1	DLA-2557-1

Notes

[stretch] - linux <not-affected> (Vulnerable code not present)
https://bugzilla.kernel.org/show_bug.cgi?id=209823
https://www.openwall.com/lists/oss-security/2021/01/12/1