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Gentoo Linux: CVE-2018-7169: Shadow: security bypass

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Gentoo Linux: CVE-2018-7169: Shadow: security bypass

Severity
5
CVSS
(AV:N/AC:L/Au:N/C:P/I:N/A:N)
Published
02/15/2018
Created
07/25/2018
Added
05/23/2018
Modified
05/23/2018

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.

Solution(s)

  • gentoo-linux-upgrade-sys-apps-shadow

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