|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, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub code/issues, web search, more)|
|NVD severity||medium (attack range: remote)|
Vulnerable and fixed packages
The table below lists information on source packages.
|shadow (PTS)||jessie (security), jessie||1:4.2-3+deb8u4||vulnerable|
The information below is based on the following data on fixed versions.
|Package||Type||Release||Fixed Version||Urgency||Origin||Debian Bugs|
[stretch] - shadow <no-dsa> (Minor issue)
[jessie] - shadow <no-dsa> (Minor issue)
[wheezy] - shadow <no-dsa> (Minor issue)