CVE-2018-12556

Name: CVE-2018-12556
Creator: NVD / NIST
Published: 2019-05-16T17:29:00.73+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

UnknownEPSS 1.77%

Last modified Jun 17, 2026

CVE-2018-12556 is a vulnerability of currently unknown severity. 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.. EPSS estimates a 1.77% chance of exploitation in the next 30 days.

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.

Metrics

EPSS Probability

1.77%

75.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-347

Affected Software

Vendor	Product	Versions
Yarnpkg	Website	<= 2018-06-05

References

http://packetstormsecurity.com/files/152703/Johnny-You-Are-Fired.htmlThird Party Advisory, VDB Entry
http://seclists.org/fulldisclosure/2019/Apr/38Mailing List, Third Party Advisory
https://github.com/RUB-NDS/Johnny-You-Are-FiredThird Party Advisory
https://github.com/RUB-NDS/Johnny-You-Are-Fired/blob/master/paper/johnny-fired.pdfThird Party Advisory
https://github.com/yarnpkg/website/commits/masterThird Party Advisory
https://www.openwall.com/lists/oss-security/2019/04/30/4Mailing List, Third Party Advisory
http://packetstormsecurity.com/files/152703/Johnny-You-Are-Fired.htmlThird Party Advisory, VDB Entry
http://seclists.org/fulldisclosure/2019/Apr/38Mailing List, Third Party Advisory
https://github.com/RUB-NDS/Johnny-You-Are-FiredThird Party Advisory
https://github.com/RUB-NDS/Johnny-You-Are-Fired/blob/master/paper/johnny-fired.pdfThird Party Advisory
https://github.com/yarnpkg/website/commits/masterThird Party Advisory
https://www.openwall.com/lists/oss-security/2019/04/30/4Mailing List, Third Party Advisory

Timeline

Published: May 16, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-12556?

How severe is CVE-2018-12556?

Severity scoring for CVE-2018-12556 is pending analysis. The EPSS model estimates a 1.77% probability of exploitation in the next 30 days.

How do I fix CVE-2018-12556?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2018-12556?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST