CVE-2018-12556
CVE-2018-12556 is a medium-severity vulnerability in Yarnpkg Website with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-347.
Key facts
- Severity: Medium (CVSS 3.x base score 5.9)
- CVSS v2: 4.3
- EPSS exploit prediction: 2% (76th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-347
- Affected product: Yarnpkg Website
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2018-12556?
- 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.
- How severe is CVE-2018-12556?
- CVE-2018-12556 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
- Is CVE-2018-12556 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2018-12556?
- CVE-2018-12556 affects Yarnpkg Website. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2018-12556?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- When was CVE-2018-12556 published?
- CVE-2018-12556 was published on 2019-05-16 and last updated on 2026-06-17.
References
- http://packetstormsecurity.com/files/152703/Johnny-You-Are-Fired.html
- http://seclists.org/fulldisclosure/2019/Apr/38
- https://github.com/RUB-NDS/Johnny-You-Are-Fired
- https://github.com/RUB-NDS/Johnny-You-Are-Fired/blob/master/paper/johnny-fired.pdf
- https://github.com/yarnpkg/website/commits/master
- https://www.openwall.com/lists/oss-security/2019/04/30/4
Affected products (1)
- cpe:2.3:a:yarnpkg:website:*:*:*:*:*:*:*:*
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