CVE-2020-36423

Name: CVE-2020-36423
Creator: NVD / NIST
Published: 2021-07-19T17:15:11.223+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.20%

Last modified Jun 17, 2026

CVE-2020-36423 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. An issue was discovered in Arm Mbed TLS before 2.23.0. A remote attacker can recover plaintext because a certain Lucky 13 countermeasure doesn't properly consider the case of a hardware accelerator.. EPSS estimates a 1.20% chance of exploitation in the next 30 days.

Description

An issue was discovered in Arm Mbed TLS before 2.23.0. A remote attacker can recover plaintext because a certain Lucky 13 countermeasure doesn't properly consider the case of a hardware accelerator.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

1.20%

64.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-319

Affected Software

Vendor	Product	Versions
Arm	Mbed Tls	< 2.16.7
Arm	Mbed Tls	>= 2.17.0, < 2.23.0
Debian	Debian Linux	10.0

References

https://bugs.gentoo.org/730752Issue Tracking, Patch, Third Party Advisory
https://github.com/ARMmbed/mbedtls/releases/tag/v2.16.7Release Notes, Third Party Advisory
https://github.com/ARMmbed/mbedtls/releases/tag/v2.23.0Release Notes, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/12/msg00036.htmlMailing List, Third Party Advisory
https://bugs.gentoo.org/730752Issue Tracking, Patch, Third Party Advisory
https://github.com/ARMmbed/mbedtls/releases/tag/v2.16.7Release Notes, Third Party Advisory
https://github.com/ARMmbed/mbedtls/releases/tag/v2.23.0Release Notes, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/12/msg00036.htmlMailing List, Third Party Advisory

Timeline

Published: Jul 19, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-36423?

An issue was discovered in Arm Mbed TLS before 2.23.0. A remote attacker can recover plaintext because a certain Lucky 13 countermeasure doesn't properly consider the case of a hardware accelerator.

How severe is CVE-2020-36423?

CVE-2020-36423 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.20% probability of exploitation in the next 30 days.

How do I fix CVE-2020-36423?

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-2020-36423?

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

Scan your code now

Source: NVD / NIST