CVE-2018-16395 : What You Need to Know

A vulnerability was found in the OpenSSL library in Ruby versions earlier than 2.3.8, 2.4.x before 2.4.5, 2.5.x before 2.5.2, and 2.6.x before 2.6.0-preview3. This issue could allow an attacker to create a fraudulent certificate that might be accepted as legitimate and used for signing or encryption operations.

Understanding CVE-2018-16395

This CVE identifies a vulnerability in the OpenSSL library used in specific versions of Ruby, potentially leading to the acceptance of fraudulent certificates.

What is CVE-2018-16395?

CVE-2018-16395 is a security vulnerability in Ruby versions prior to 2.3.8, 2.4.x before 2.4.5, 2.5.x before 2.5.2, and 2.6.x before 2.6.0-preview3. It arises from incorrect evaluation of instances of OpenSSL::X509::Name when using the == operator.

The Impact of CVE-2018-16395

Exploiting this vulnerability could result in the creation of a fake certificate that may be treated as legitimate, enabling unauthorized signing or encryption activities.

Technical Details of CVE-2018-16395

This section delves into the specifics of the vulnerability.

Vulnerability Description

When comparing two instances of OpenSSL::X509::Name using the == operator, the result may be true for non-equal objects depending on their order, potentially leading to the acceptance of fraudulent certificates.

Affected Systems and Versions

Ruby versions earlier than 2.3.8, 2.4.x before 2.4.5, 2.5.x before 2.5.2, and 2.6.x before 2.6.0-preview3.

Exploitation Mechanism

The vulnerability arises when comparing instances of OpenSSL::X509::Name using the == operator, allowing for the creation of fraudulent certificates.

Mitigation and Prevention

Protective measures to address CVE-2018-16395.

Immediate Steps to Take

Update Ruby to versions 2.3.8, 2.4.5, 2.5.2, or 2.6.0-preview3 to mitigate the vulnerability.
Monitor for any unauthorized certificate signings or encryption activities.

Long-Term Security Practices

Regularly update Ruby and associated libraries to the latest secure versions.
Implement certificate validation checks to detect fraudulent certificates.

Patching and Updates

Apply patches provided by Ruby for the affected versions to fix the OpenSSL library vulnerability.