CVE-2021-37155 : What You Need to Know

A vulnerability in wolfSSL versions 4.6.x through 4.7.x before 4.8.0 could allow an attacker to bypass security measures.

Understanding CVE-2021-37155

This CVE involves wolfSSL not generating a failure outcome when there is a discrepancy in serial numbers between an OCSP request and response.

What is CVE-2021-37155?

wolfSSL versions 4.6.x through 4.7.x before 4.8.0 fail to indicate an error when the serial number in an OCSP request does not match the serial number in the corresponding response.

The Impact of CVE-2021-37155

This issue could be exploited by an adversary to potentially bypass security controls and perform unauthorized actions within affected systems.

Technical Details of CVE-2021-37155

Within the wolfSSL library, this vulnerability arises due to the lack of validation for serial number consistency in OCSP requests and responses.

Vulnerability Description

The vulnerability in wolfSSL versions 4.6.x through 4.7.x before 4.8.0 stems from the absence of proper error handling when serial numbers in OCSP requests and responses do not match.

Affected Systems and Versions

All instances of wolfSSL versions 4.6.x through 4.7.x before 4.8.0 are impacted by this vulnerability.

Exploitation Mechanism

By exploiting the lack of failure outcome generation in OCSP serial number checks, threat actors could potentially evade security mechanisms and carry out malicious activities.

Mitigation and Prevention

To address CVE-2021-37155, immediate actions and long-term security measures are recommended.

Immediate Steps to Take

Users are advised to update wolfSSL to version 4.8.0 or later, where the security flaw has been fixed.

Long-Term Security Practices

Maintain a proactive approach to software security by regularly applying patches and updates, conducting security assessments, and monitoring for any unusual activity.

Patching and Updates

Refer to the official wolfSSL repository for the latest patches and updates to mitigate the vulnerability.