CVE-2020-36242: PyCA Cryptography symmetrically encrypting large values can lead to integer overflow

CVE-2020-36242 · Severity: low · CVSS 3.1 · Published 2021-02-07

In the cryptography package before 3.3.2 for Python, certain sequences of update calls to symmetrically encrypt multi-GB values could result in an integer overflow and buffer overflow, as demonstrated by the Fernet class.

Technologies: cryptography (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2020-36242 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2020-36242 being exploited in the wild.
How severe is CVE-2020-36242?
Low severity, with a CVSS score of 3.1, published 7 February 2021.
Which products and versions are affected?
cryptography (PyPI) ECOSYSTEM:introduced=3.1,fixed=3.3.2.
Is there a fix for CVE-2020-36242?
Yes. cryptography (PyPI): upgrade to 3.3.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2020-36242?
Check whether you run cryptography (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • cryptography (PyPI): upgrade to 3.3.2 or later
    pip install "cryptography>=3.3.2"

Affected products

  • cryptography (PyPI) ECOSYSTEM:introduced=3.1,fixed=3.3.2

Identifiers

  • CVE-2020-36242
  • GHSA-rhm9-p9w5-fwm7
  • PYSEC-2021-63

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