Cyber Resilience

CVE-2021-43571

CriticalPublic PoC

Published: 09 November 2021

Published
09 November 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0022 44.9th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-43571 is a critical-severity Improper Verification of Cryptographic Signature (CWE-347) vulnerability in Starkbank Ecdsa-Node. Its CVSS base score is 9.8 (Critical).

Operationally, ranked at the 44.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

The verify function in the Stark Bank Node.js ECDSA library (ecdsa-node) 1.1.2 fails to check that the signature is non-zero, which allows attackers to forge signatures on arbitrary messages.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

starkbank
ecdsa-node
1.1.2

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-347

Requires verification of digital signatures using organization-approved certificates before installation, directly preventing improper verification of cryptographic signatures.

addresses: CWE-347

Component authenticity commonly depends on cryptographic signatures; the control enforces proper verification of those signatures.

addresses: CWE-347

PKI certificates under an approved policy require cryptographic signature verification on issuance and validation.

addresses: CWE-347

Requires cryptographic signatures on authoritative data and support for verifying the chain of trust.

addresses: CWE-347

Mandates verification of cryptographic signatures (e.g., DNSSEC RRSIG) on resolution responses, addressing missing or bypassed signature checks.

addresses: CWE-347

Integrity tools commonly rely on cryptographic signatures whose improper validation this weakness covers.

addresses: CWE-347

Authenticity validation commonly relies on cryptographic signature or certificate checks that this control enforces.

References