Timing Attack Affecting fastecdsa package, versions [,2.1.2)


Severity

Recommended
0.0
low
0
10

CVSS assessment made by Snyk's Security Team

    Threat Intelligence

    EPSS
    0.24% (65th percentile)

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  • Snyk ID SNYK-PYTHON-FASTECDSA-570964
  • published 3 Jun 2020
  • disclosed 3 Jun 2020
  • credit Unknown

How to fix?

Upgrade fastecdsa to version 2.1.2 or higher.

Overview

fastecdsa is a python package for doing fast elliptic curve cryptography, specifically digital signatures.

Affected versions of this package are vulnerable to Timing Attack. When using the NIST P-256 curve in the ECDSA implementation, the point at infinity is mishandled. This means that for an extreme value in k and s^-1, the signature verification fails even if the signature is correct. There are some threat models where an attacker can benefit by successfully guessing users for whom signature verification will fail.

CVSS Scores

version 3.1
Expand this section

Snyk

Recommended
3.7 low
  • Attack Vector (AV)
    Network
  • Attack Complexity (AC)
    High
  • Privileges Required (PR)
    None
  • User Interaction (UI)
    None
  • Scope (S)
    Unchanged
  • Confidentiality (C)
    None
  • Integrity (I)
    Low
  • Availability (A)
    None
Expand this section

NVD

7.5 high