CVE-2018-7169 Information

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.

CVSS Vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Reference

https://bugs.launchpad.net/ubuntu/+source/shadow/+bug/1729357 https://security.gentoo.org/glsa/201805-09

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

LOW

Availability Impact

NONE

Base Score

NONE

Base Severity

5.3