CVE-2021-43572

Q: How do I fix CVE-2021-43572?

Upgrade ecdsa-python to 2.0.1 or later.

Q: Is CVE-2021-43572 being actively exploited?

Not that we know of. CVE-2021-43572 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 1.2% is the estimated probability that it will be exploited in the next 30 days. That is higher than 65% of all scored CVEs.

Q: How severe is CVE-2021-43572?

CVE-2021-43572 has a CVSS v3 base score of 9.8, rated critical. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

Q: What does CVE-2021-43572 affect?

Published advisories record a fix for ecdsa-python (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

CRITICAL

9.8

CVSS v3

NVD

Description

The verify function in the Stark Bank Python ECDSA library (aka starkbank-escada or ecdsa-python) before 2.0.1 fails to check that the signature is non-zero, which allows attackers to forge signatures on arbitrary messages.

CWE-347

How to fix

Remediation Available

ecdsa-pythonNVD

Affected:< 2.0.1Fixed in:2.0.1CVE-2021-43572derived from NVD

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploit Intelligence

1.20%probability of exploitation in 30 days

65thpercentile

Moderate risk: more likely to be exploited than 65% of all known CVEs.

References

Patch1

github.com

Exploit1

research.nccgroup.com

Third-Party Advisory1

github.com

Related Vulnerabilities

Other CWE-347 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2018-16042	Medium	6.5	82%	-	-
CVE-2025-25292	Critical	9.8	65%	-	Fix
CVE-2025-59718	Critical	9.8	63%	KEV	Fix
CVE-2021-22160	Critical	9.8	53%	-	Fix
CVE-2013-3900	Medium	5.5	45%	KEV	-
CVE-2018-0114	High	7.5	43%	-	Fix

Common questions

How do I fix CVE-2021-43572?

Upgrade ecdsa-python to 2.0.1 or later.

Is CVE-2021-43572 being actively exploited?

Not that we know of. CVE-2021-43572 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 1.2% is the estimated probability that it will be exploited in the next 30 days. That is higher than 65% of all scored CVEs.

How severe is CVE-2021-43572?

CVE-2021-43572 has a CVSS v3 base score of 9.8, rated critical. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2021-43572 affect?

Published advisories record a fix for ecdsa-python (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

Embed a live status badge for CVE-2021-43572

Markdown

[![CVE-2021-43572](https://tridentstack.com/cve/badge/CVE-2021-43572.svg)](https://tridentstack.com/cve/CVE-2021-43572)

HTML

<a href="https://tridentstack.com/cve/CVE-2021-43572"><img src="https://tridentstack.com/cve/badge/CVE-2021-43572.svg" alt="CVE-2021-43572"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

See how it works Start freeThis CVE lookup is free and always will be.

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.