CVE-2018-12556

Publication date 16 May 2019

Last updated 11 July 2025

Ubuntu priority

Cvss 3 Severity Score

Description

The signature verification routine in install.sh in yarnpkg/website through 2018-06-05 only verifies that the yarn release is signed by any (arbitrary) key in the local keyring of the user, and does not pin the signature to the yarn release key, which allows remote attackers to sign tampered yarn release packages with their own key.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
node-yarnpkg	25.10 questing	Needs evaluation
	25.04 plucky	Needs evaluation
	24.10 oracular	Ignored end of life, was needs-triage
	24.04 LTS noble	Needs evaluation
	23.10 mantic	Ignored end of life, was needs-triage
	23.04 lunar	Ignored end of life, was needs-triage
	22.10 kinetic	Ignored end of life, was needs-triage
	22.04 LTS jammy	Needs evaluation
	21.10 impish	Ignored end of life
	21.04 hirsute	Ignored end of life
	20.10 groovy	Ignored end of life
	20.04 LTS focal	Needs evaluation
	19.10 eoan	Ignored end of life
	19.04 disco	Ignored end of life
	18.10 cosmic	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release

Notes

seth-arnold

It appears this is about the install.sh that is run via a curl url | bash - auto-updated mechanism inside the program. It looks like it tries to determine if it was installed via deb and if so, runs: sudo apt-get update && sudo apt-get install yarn So it's possible the unsafe mechanism isn't used in our packages. It's also possible this is seriously unsafe.

Severity score breakdown

Parameter	Value
Base score	5.9 · Medium
Attack vector	Network
Attack complexity	High
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	High
Availability impact	None
Vector	CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N