CVE-2021-43570

CRITICALNVD 9.89.8—

9.8

The verify function in the Stark Bank Java ECDSA library (ecdsa-java) 1.0.0 fails to check that the signature is non-zero, which allows attackers to forge signatures on arbitrary messages.

CVSS v3: 9.8
EG Score: 9.8(medium)
EPSS: 44.6%
KEV: Not listed

Published

November 9, 2021

Last Modified

November 21, 2024

Advisory Details (2)

Auto-updated May 26, 2026

Patch available. Sources: github_release.

generic

Cyber Security Research | NCC Group

https://research.nccgroup.com/2021/11/08/technical-advisory-arbitrary-signature-forgery-in-stark-bank-ecdsa-libraries/

github_release Patch Available

v1.0.1

Patch available: starkbank/ecdsa-java v1.0.1

https://github.com/starkbank/ecdsa-java/releases/tag/v1.0.1

Affected Packages

(1 across 1 ecosystem)

Maven(1)

Package	Vulnerable range	Fixed in	Dependents
com.starkbank.ellipticcurve:starkbank-ecdsa	1.0.0	1.0.1	—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-347Improper Verification of Cryptographic Signature

Data Freshness Timeline

(refreshed 8× in last 7d / 8× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-05-27 13:39 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 13:42 UTCepss_batch
2026-05-26 13:42 UTCepss_batch
2026-05-26 07:47 UTCEG score recompute
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch

Frequently asked(5)

What is CVE-2021-43570?

CVE-2021-43570 is a critical vulnerability published on November 9, 2021. The verify function in the Stark Bank Java ECDSA library (ecdsa-java) 1.0.0 fails to check that the signature is non-zero, which allows attackers to forge signatures on arbitrary messages.

When was CVE-2021-43570 disclosed?

CVE-2021-43570 was first published in the National Vulnerability Database on November 9, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-43570 actively exploited?

CVE-2021-43570 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 44.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-43570?

CVE-2021-43570 has a CVSS v3 base score of 9.8 (NVD).

How do I remediate CVE-2021-43570?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-43570, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-43570

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