CVE-2018-7169

Publication date 15 February 2018

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

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.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
shadow	22.04 LTS jammy	Not affected
	21.10 impish	Not affected
	21.04 hirsute	Not affected
	20.10 groovy	Not affected
	20.04 LTS focal	Not affected
	19.10 eoan	Ignored end of life
	19.04 disco	Ignored end of life
	18.10 cosmic	Ignored end of life
	18.04 LTS bionic	Fixed 1:4.5-1ubuntu2.2
	17.10 artful	Ignored end of life
	16.04 LTS xenial	Fixed 1:4.2-3.1ubuntu5.5+esm1
	14.04 LTS trusty	Fixed 1:4.1.5.1-1ubuntu9.5+esm1

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Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
shadow	Upstream: fb28c99

Severity score breakdown

Parameter	Value
Base score	5.3 · Medium
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	Low
Integrity impact	None
Availability impact	None
Vector	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

References

Related Ubuntu Security Notices (USN)

USN-5254-1
shadow vulnerabilities
27 January 2022