CVE-2018-7169

Name	CVE-2018-7169
Description	An issue was discovered in shadow 4.5. newgidmap (in shadow-utils) is setuid and allows an unprivileged user to be placed in a user namespace where setgroups(2) is permitted. This allows an attacker to remove themselves from a supplementary group, which may allow access to certain filesystem paths if the administrator has used "group blacklisting" (e.g., chmod g-rwx) to restrict access to paths. This flaw effectively reverts a security feature in the kernel (in particular, the /proc/self/setgroups knob) to prevent this sort of privilege escalation.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	ELA-1220-1, ELA-555-1
Debian Bugs	890557

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
shadow (PTS)	jessie, jessie (lts)	1:4.2-3+deb8u5	fixed
	stretch (security)	1:4.4-4.1+deb9u1	vulnerable
	stretch (lts), stretch	1:4.4-4.1+deb9u2	fixed
	buster, buster (lts)	1:4.5-1.1+deb10u1	fixed
	bullseye	1:4.8.1-1	fixed
	bookworm	1:4.13+dfsg1-1	fixed
	sid, trixie	1:4.16.0-7	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
shadow	source	jessie	1:4.2-3+deb8u5		ELA-555-1
shadow	source	stretch	1:4.4-4.1+deb9u2		ELA-1220-1
shadow	source	buster	1:4.5-1.1+deb10u1		ELA-1220-1
shadow	source	(unstable)	1:4.7-1	low		890557

Notes

[buster] - shadow <no-dsa> (Minor issue)
[stretch] - shadow <no-dsa> (Minor issue)
[jessie] - shadow <no-dsa> (Minor issue)
[wheezy] - shadow <no-dsa> (Minor issue)
https://bugs.launchpad.net/ubuntu/+source/shadow/+bug/1729357
https://github.com/shadow-maint/shadow/pull/97