CVE-2020-36843: Signature Bypass (CVSS 4.3)

Description

The implementation of EdDSA in EdDSA-Java (aka ed25519-java) through 0.3.0 exhibits signature malleability and does not satisfy the SUF-CMA (Strong Existential Unforgeability under Chosen Message Attacks) property. This allows attackers to create new valid signatures different from previous signatures for a known message.

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CVSS v3.1 Score

4.3

MEDIUM

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

Weakness Type (CWE)

CWE-347 CWE-347

References

Other References

https://eprint.iacr.org/2020/1244 https://github.com/str4d/ed25519-java/issues/82#issue-727629226

Frequently Asked Questions

What is CVE-2020-36843? +

The implementation of EdDSA in EdDSA-Java (aka ed25519-java) through 0.3.0 exhibits signature malleability and does not satisfy the SUF-CMA (Strong Existential Unforgeability under Chosen Message Attacks) property. This allows attackers to create new valid signatures different from previous signatures for a known message. It has a CVSS v3.1 base score of 4.3 (MEDIUM).

How severe is CVE-2020-36843? +

CVE-2020-36843 has a CVSS v3.1 score of 4.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

How do I check if I'm vulnerable to CVE-2020-36843? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2020-36843