CVE-2020-36421 Information disclosure in n/a

What is CVE-2020-36421?

CVE-2020-36421 is a medium-severity vulnerability in Arm Mbed Tls, published on 19 Jul 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

An issue was discovered in Arm Mbed TLS before 2.23.0. Because of a side channel in modular exponentiation, an RSA private key used in a secure enclave could be disclosed.

Weakness: CWE-203

Which versions are affected by CVE-2020-36421?

It affects 2 products.

Products include Arm Mbed Tls, Debian Debian Linux.

How do I fix CVE-2020-36421?

Upgrade to a fixed version.

Is CVE-2020-36421 being exploited?

There is no known exploitation of CVE-2020-36421 in the wild and no public exploit code.

Other vulnerabilities in Arm Mbed Tls

• CVE-2026-34877 Deserialization in n/a Critical 9.8
• CVE-2022-46393 Memory corruption in n/a Critical 9.8
• CVE-2021-44732 Use after free in n/a Critical 9.8
• CVE-2017-18187 Integer overflow in n/a Critical 9.8
• CVE-2018-0487 Memory corruption in ARM mbed TLS before 1.3.22, before 2.1.10, and before 2.7.0 Critical 9.8

All Arm Mbed Tls vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2020-36421, GHSA-4h9j-8g4q-fcfq, JLSEC-2025-204, UBUNTU-CVE-2020-36421.