CVE-2018-12556

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.

Category

5.9
CVSS
Severity: Medium
CVSS 3.0 •
CVSS 2.0 •
EPSS 0.34%
Third-Party Advisory packetstormsecurity.com Third-Party Advisory seclists.org Third-Party Advisory github.com Third-Party Advisory github.com Third-Party Advisory github.com Third-Party Advisory openwall.com
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://github.com/yarnpkg/website/commits/master third party advisory
http://seclists.org/fulldisclosure/2019/Apr/38 third party advisory mailing list
http://packetstormsecurity.com/files/152703/Johnny-You-Are-Fired.html vdb entry third party advisory
https://www.openwall.com/lists/oss-security/2019/04/30/4 third party advisory mailing list
https://github.com/RUB-NDS/Johnny-You-Are-Fired third party advisory
https://github.com/RUB-NDS/Johnny-You-Are-Fired/blob/master/paper/johnny-fired.pdf third party advisory

Frequently Asked Questions

What is the severity of CVE-2018-12556?
CVE-2018-12556 has been scored as a medium severity vulnerability.
How to fix CVE-2018-12556?
To fix CVE-2018-12556, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2018-12556 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2018-12556 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.