CVE-2020-36421 Explained : Impact and Mitigation

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

Understanding CVE-2020-36421

This CVE identifies a vulnerability in Arm Mbed TLS that could lead to the disclosure of an RSA private key used in a secure enclave.

What is CVE-2020-36421?

CVE-2020-36421 is a security vulnerability found in Arm Mbed TLS versions prior to 2.23.0. The issue arises from a side channel in modular exponentiation, potentially exposing an RSA private key.

The Impact of CVE-2020-36421

The exploitation of this vulnerability could result in the unauthorized disclosure of sensitive RSA private key information, compromising the security of systems utilizing Arm Mbed TLS.

Technical Details of CVE-2020-36421

Arm Mbed TLS vulnerability details.

Vulnerability Description

The vulnerability in Arm Mbed TLS before version 2.23.0 allows for the disclosure of an RSA private key due to a side channel in modular exponentiation.

Affected Systems and Versions

Vendor: n/a
Product: n/a
Versions: All versions before 2.23.0 are affected.

Exploitation Mechanism

The vulnerability can be exploited through side-channel attacks on the modular exponentiation process, potentially leading to the exposure of RSA private key information.

Mitigation and Prevention

Protecting systems from CVE-2020-36421.

Immediate Steps to Take

Update Arm Mbed TLS to version 2.23.0 or newer to mitigate the vulnerability.
Monitor for any unauthorized access or unusual activities on systems using Arm Mbed TLS.

Long-Term Security Practices

Implement secure coding practices to prevent similar vulnerabilities in cryptographic implementations.
Regularly review and update cryptographic libraries and dependencies to address known security issues.

Patching and Updates

Apply patches and updates provided by Arm Mbed TLS to address the vulnerability and enhance the security of the cryptographic implementation.