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

Source: https://junglewise.ai/threats/cve-2020-36242-pyca-cryptography-symmetrically-encrypting-large-values-can-lead  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2021-02-07  
License: CC BY 4.0 with a link back

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)](https://junglewise.ai/threats/technologies/cryptography). Vendors: [PyPI](https://junglewise.ai/threats/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

  ```sh
  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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