Authentication Bypass Affecting cryptography package, versions [1.9.0,2.3)


Severity

Recommended
0.0
high
0
10

CVSS assessment made by Snyk's Security Team

    Threat Intelligence

    EPSS
    0.18% (56th percentile)

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  • Snyk ID SNYK-PYTHON-CRYPTOGRAPHY-42164
  • published 19 Jul 2018
  • disclosed 17 Jul 2018
  • credit Unknown

How to fix?

Upgrade cryptography to version 2.3 or higher.

Overview

cryptography is a package which provides cryptographic recipes and primitives to Python developers.

Affected versions of this package are vulnerable to Authentication Bypass. The finalize_with_tag API did not enforce a minimum tag length. If a user did not validate the input length prior to passing it to finalize_with_tag an attacker could craft an invalid payload with a shortened tag (e.g. 1 byte) giving them a 1 in 256 chance of passing the MAC check.

CVSS Scores

version 3.1
Expand this section

Snyk

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