CVE-2020-22741Public exploitNetwork attack vector

Private-key recovery via exposed multisignature nonce

Published Jul 19, 2021 · Updated Aug 4, 2024

Cryptographic key disclosure in Xuperchain 3.6.0 allows remote attackers to recover a user's private key from a multisignature. The workflow exposes each signer's nonce in KList, so a proposer holding the matching partial signature can solve sk=(s-k)/H(PK,R,m). Possession of a participant's partial signature and public transaction context is sufficient to derive that participant's P-256 private key.

CVSS severity7.5
High
EPSS probability0.83%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cryptographic key disclosure in Xuperchain 3.6.0 allows remote attackers to recover a user's private key from a multisignature. The workflow exposes each signer's nonce in KList, so a proposer holding the matching partial signature can solve sk=(s-k)/H(PK,R,m). Possession of a participant's partial signature and public transaction context is sufficient to derive that participant's P-256 private key.

The record

CVE
CVE-2020-22741
Published
Jul 19, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-312
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 19, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-312Cleartext Storage of Sensitive Information

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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