CVE-2020-36242

Name: CVE-2020-36242
Creator: NVD / NIST
Published: 2021-02-07T20:15:12.09+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.1/10EPSS 6.72%

Last modified Jun 17, 2026

CVE-2020-36242 is a critical-severity vulnerability rated 9.1/10 on the CVSS scale. 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.. EPSS estimates a 6.72% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

9.1/10

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

EPSS Probability

6.72%

93.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cryptography.Io	Cryptography	< 3.3.2
Fedoraproject	Fedora	33
Oracle	Communications Cloud Native Core Network Function Cloud Native Environment	1.10.0

References

https://github.com/pyca/cryptography/blob/master/CHANGELOG.rstRelease Notes, Third Party Advisory
https://github.com/pyca/cryptography/compare/3.3.1...3.3.2Patch, Third Party Advisory
https://github.com/pyca/cryptography/issues/5615Exploit, Patch, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L7RGQLK4J5ZQFRLKCHVVG6BKZTUQMG7E/
https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
https://www.oracle.com/security-alerts/cpujul2022.htmlPatch, Third Party Advisory
https://github.com/pyca/cryptography/blob/master/CHANGELOG.rstRelease Notes, Third Party Advisory
https://github.com/pyca/cryptography/compare/3.3.1...3.3.2Patch, Third Party Advisory
https://github.com/pyca/cryptography/issues/5615Exploit, Patch, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L7RGQLK4J5ZQFRLKCHVVG6BKZTUQMG7E/
https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
https://www.oracle.com/security-alerts/cpujul2022.htmlPatch, Third Party Advisory

Timeline

Published: Feb 7, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-36242?

How severe is CVE-2020-36242?

CVE-2020-36242 has a CVSS score of 9.1/10 (CRITICAL severity). The EPSS model estimates a 6.72% probability of exploitation in the next 30 days.

How do I fix CVE-2020-36242?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-36242?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST