CVE-2021-3671

Name	CVE-2021-3671
Description	A null pointer de-reference was found in the way samba kerberos server handled missing sname in TGS-REQ (Ticket Granting Server - Request). An authenticated user could use this flaw to crash the samba server.
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-3206-1, DSA-5287-1, ELA-795-1, ELA-797-1
Debian Bugs	996586

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
heimdal (PTS)	jessie, jessie (lts)	1.6~rc2+dfsg-9+deb8u3	fixed
	stretch (security)	7.1.0+dfsg-13+deb9u3	vulnerable
	stretch (lts), stretch	7.1.0+dfsg-13+deb9u4	fixed
	buster	7.5.0+dfsg-3	vulnerable
	buster (security)	7.5.0+dfsg-3+deb10u2	fixed
	bullseye (security), bullseye	7.7.0+dfsg-2+deb11u3	fixed
	bookworm	7.8.git20221117.28daf24+dfsg-2	fixed
	sid, trixie	7.8.git20221117.28daf24+dfsg-5	fixed
samba (PTS)	jessie, jessie (lts)	2:4.2.14+dfsg-0+deb8u15	vulnerable
	stretch (security), stretch (lts), stretch	2:4.5.16+dfsg-1+deb9u4	vulnerable
	buster	2:4.9.5+dfsg-5+deb10u3	vulnerable
	buster (security)	2:4.9.5+dfsg-5+deb10u5	vulnerable
	bullseye	2:4.13.13+dfsg-1~deb11u5	fixed
	bullseye (security)	2:4.13.13+dfsg-1~deb11u6	fixed
	bookworm (security), bookworm	2:4.17.12+dfsg-0+deb12u1	fixed
	trixie	2:4.19.6+dfsg-1	fixed
	sid	2:4.19.6+dfsg-3	fixed

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

Package	Type	Release	Fixed Version	Origin	Debian Bugs
heimdal	source	jessie	1.6~rc2+dfsg-9+deb8u3	ELA-797-1
heimdal	source	stretch	7.1.0+dfsg-13+deb9u4	ELA-795-1
heimdal	source	buster	7.5.0+dfsg-3+deb10u1	DLA-3206-1
heimdal	source	bullseye	7.7.0+dfsg-2+deb11u2	DSA-5287-1
heimdal	source	(unstable)	7.7.0+dfsg-3		996586
samba	source	bullseye	2:4.13.13+dfsg-1~deb11u1
samba	source	(unstable)	2:4.13.13+dfsg-1

Notes

[stretch] - heimdal <no-dsa> (Minor issue)
[buster] - samba <ignored> (Domain controller functionality is EOLed, see DSA-5015-1)
[stretch] - samba <no-dsa> (Minor issue)
https://bugzilla.redhat.com/show_bug.cgi?id=2013080
https://bugzilla.samba.org/show_bug.cgi?id=14770
https://github.com/heimdal/heimdal/security/advisories/GHSA-h9qj-cpmq-3562
Fixed by: https://github.com/heimdal/heimdal/commit/04171147948d0a3636bc6374181926f0fb2ec83a
Followup: https://github.com/heimdal/heimdal/commit/773802aecfb4b6a73817fa522faeb55b2a7cdb2a
"Equivalent" issue for CVE-2021-37750 for the MIT krb5 vulnerability.
Fixed by (Samba): https://gitlab.com/samba-team/samba/-/commit/0cb4b939f192376bf5e33637863a91a20f74c5a5
[jessie] - samba <ignored> (Minor issue; affects Samba as AD DC; EOLed)
<ignored> also in stretch because it affects Samba as AD DC; EOLed