CVE-2020-36422

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-07-19 · updated 2026-06-17
Weakness: CWE-203

Description

An issue was discovered in Arm Mbed TLS before 2.23.0. A side channel allows recovery of an ECC private key, related to mbedtls_ecp_check_pub_priv, mbedtls_pk_parse_key, mbedtls_pk_parse_keyfile, mbedtls_ecp_mul, and mbedtls_ecp_mul_restartable.

Affected products

mbedtls: before 2.16.7; from 2.17.0 before 2.23.0 — fixed in 2.16.7, 2.23.0
Debian Linux: 10.0

How to fix

Upgrade to a fixed version: mbedtls 2.16.7, 2.23.0. Check the vendor advisory for mitigations.

References

https://bugs.gentoo.org/730752
https://github.com/ARMmbed/mbedtls/releases/tag/v2.16.7
https://github.com/ARMmbed/mbedtls/releases/tag/v2.23.0
https://lists.debian.org/debian-lts-announce/2022/12/msg00036.html
https://bugs.gentoo.org/730752
https://github.com/ARMmbed/mbedtls/releases/tag/v2.16.7
https://github.com/ARMmbed/mbedtls/releases/tag/v2.23.0
https://lists.debian.org/debian-lts-announce/2022/12/msg00036.html

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