PT-2021-23874 · Stark Bank · Stark Bank .Net Ecdsa Library

Published 2021-11-09 · Updated 2021-11-12 · CVE-2021-43569

Positive Technologies (AI Summary)

CVSS v3.1

9.8

Critical

Base vector

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

Name of the Vulnerable Software and Affected Versions Stark Bank .NET ECDSA library (ecdsa-dotnet) version 1.3.1

Description The verify function in the library fails to check that the signature is non-zero, allowing attackers to forge signatures on arbitrary messages.

Recommendations For version 1.3.1, consider disabling the verify function until a patch is available to prevent attackers from forging signatures. At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Improper Verification of Cryptographic Signature

Weakness Enumeration

CWE-347

Related Identifiers

CVE-2021-43569

GHSA-J3JW-J2J8-2WV9

Affected Products

Stark Bank .Net Ecdsa Library

References · 7

• 🔥 https://research.nccgroup.com/2021/11/08/technical-advisory-arbitrary-signature-forgery-in-stark-bank-ecdsa-libraries · Exploit
• https://osv.dev/vulnerability/CVE-2021-43569 · Vendor Advisory
• https://osv.dev/vulnerability/GHSA-j3jw-j2j8-2wv9 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-43569 · Security Note
• https://github.com/starkbank/ecdsa-dotnet/releases/tag/v1.3.2 · Note
• https://github.com/starkbank/ecdsa-dotnet · Note
• https://t.me/cibsecurity/32121 · Telegram Post