Signature forgery via unchecked zero-value components
Published Nov 9, 2021 · Updated Aug 4, 2024
Improper signature verification in Stark Bank ecdsa-node 1.1.2 allows remote attackers to forge signatures for arbitrary messages. The verify function omits range checks for r and s, and Math.inv returns zero for s=0, reducing the final signature comparison to 0==0. Exploitation requires a consuming application to verify an attacker-supplied signature; the forged (0, 0) signature validates under any public key.
Summary
What happened
Improper signature verification in Stark Bank ecdsa-node 1.1.2 allows remote attackers to forge signatures for arbitrary messages. The verify function omits range checks for r and s, and Math.inv returns zero for s=0, reducing the final signature comparison to 0==0. Exploitation requires a consuming application to verify an attacker-supplied signature; the forged (0, 0) signature validates under any public key.
The record
- CVE
- CVE-2021-43571
- Published
- Nov 9, 2021
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-347
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Nov 9, 2021CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- NCC Group zero-signature demonstrationproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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