CVE-2018-7738

Publication date 7 March 2018

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

In util-linux before 2.32-rc1, bash-completion/umount allows local users to gain privileges by embedding shell commands in a mountpoint name, which is mishandled during a umount command (within Bash) by a different user, as demonstrated by logging in as root and entering umount followed by a tab character for autocompletion.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
bash-completion	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	Not affected
	17.10 artful	Ignored end of life
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected
util-linux	20.04 LTS focal	Not affected
	19.10 eoan	Not affected
	19.04 disco	Not affected
	18.10 cosmic	Not affected
	18.04 LTS bionic	Fixed 2.31.1-0.4ubuntu3.7
	17.10 artful	Ignored end of life
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected

Notes

sbeattie

bash completion for umount moved from bash-completion to util-linux in util-linux 2.28-1

mdeslaur

script in xenial bash-completion package isn't vulnerable bash-completion package in bionic+ doesn't contain the umount helper

Patch details

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

Package	Patch details
util-linux	Upstream: 75f03ba

Severity score breakdown

Parameter	Value
Base score	7.8 · High
Attack vector	Local
Attack complexity	Low
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	High
Availability impact	High
Vector	CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H