CVE-2021-36222

Name	CVE-2021-36222
Description	ec_verify in kdc/kdc_preauth_ec.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.18.4 and 1.19.x before 1.19.2 allows remote attackers to cause a NULL pointer dereference and daemon crash. This occurs because a return value is not properly managed in a certain situation.
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	DSA-4944-1
Debian Bugs	991365

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
krb5 (PTS)	buster	1.17-3+deb10u4	fixed
	buster (security)	1.17-3+deb10u5	fixed
	bullseye (security), bullseye	1.18.3-6+deb11u3	fixed
	bookworm, sid	1.20.1-2	fixed

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

Package	Type	Release	Fixed Version	Origin	Debian Bugs
krb5	source	stretch	(not affected)
krb5	source	buster	1.17-3+deb10u2	DSA-4944-1
krb5	source	(unstable)	1.18.3-6		991365

Notes

[stretch] - krb5 <not-affected> (Vulnerable code (k5memdup0()) introduced later)
https://github.com/krb5/krb5/commit/fc98f520caefff2e5ee9a0026fdf5109944b3562
http://krbdev.mit.edu/rt/Ticket/Display.html?id=9007