CVE-2020-36476 Explained : Impact and Mitigation

An issue was discovered in Mbed TLS before 2.24.0 (and before 2.16.8 LTS and before 2.7.17 LTS). There is missing zeroization of plaintext buffers in mbedtls_ssl_read to erase unused application data from memory.

Understanding CVE-2020-36476

This CVE identifies a vulnerability in Mbed TLS versions prior to 2.24.0, where plaintext buffers are not properly zeroized in mbedtls_ssl_read, potentially leaving sensitive data in memory.

What is CVE-2020-36476?

CVE-2020-36476 is a security flaw in Mbed TLS that could allow an attacker to access sensitive information left in memory due to missing zeroization of plaintext buffers.

The Impact of CVE-2020-36476

This vulnerability could lead to unauthorized access to sensitive data, compromising the confidentiality of information processed by affected systems.

Technical Details of CVE-2020-36476

Mbed TLS versions before 2.24.0, 2.16.8 LTS, and 2.7.17 LTS are affected by this issue.

Vulnerability Description

The vulnerability arises from the failure to properly clear plaintext buffers, potentially exposing sensitive data to unauthorized access.

Affected Systems and Versions

Vendor: n/a
Product: n/a
Versions: All versions before 2.24.0, 2.16.8 LTS, and 2.7.17 LTS

Exploitation Mechanism

Attackers could exploit this vulnerability by accessing and retrieving sensitive information left in memory due to the lack of zeroization of plaintext buffers.

Mitigation and Prevention

It is crucial to take immediate steps to address and prevent exploitation of this vulnerability.

Immediate Steps to Take

Update Mbed TLS to version 2.24.0 or newer to mitigate the vulnerability.
Monitor and restrict access to sensitive data processed by affected systems.

Long-Term Security Practices

Implement secure coding practices to ensure proper handling of sensitive data.
Regularly review and update security protocols to address potential vulnerabilities.

Patching and Updates

Apply patches provided by Mbed TLS to fix the vulnerability.