CVE-2021-3738

Name	CVE-2021-3738
Description	In DCE/RPC it is possible to share the handles (cookies for resource state) between multiple connections via a mechanism called 'association groups'. These handles can reference connections to our sam.ldb database. However while the database was correctly shared, the user credentials state was only pointed at, and when one connection within that association group ended, the database would be left pointing at an invalid 'struct session_info'. The most likely outcome here is a crash, but it is possible that the use-after-free could instead allow different user state to be pointed at and this might allow more privileged access.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DSA-5003-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
samba (PTS)	buster	2:4.9.5+dfsg-5+deb10u3	vulnerable
	buster (security)	2:4.9.5+dfsg-5+deb10u4	vulnerable
	bullseye	2:4.13.13+dfsg-1~deb11u5	fixed
	bullseye (security)	2:4.13.13+dfsg-1~deb11u6	fixed
	bookworm, bookworm (security)	2:4.17.12+dfsg-0+deb12u1	fixed
	trixie	2:4.19.5+dfsg-1	fixed
	sid	2:4.19.6+dfsg-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
samba	source	bullseye	2:4.13.13+dfsg-1~deb11u2		DSA-5003-1
samba	source	(unstable)	2:4.13.14+dfsg-1

Notes

[buster] - samba <no-dsa> (Minor issue; affects Samba as AD DC)
https://bugzilla.samba.org/show_bug.cgi?id=14468
https://www.samba.org/samba/security/CVE-2021-3738.html