CVE-2022-39218 : Security Advisory and Response

This article provides detailed information about CVE-2022-39218, a vulnerability in the JS Compute Runtime for Fastly's Compute@Edge platform.

Understanding CVE-2022-20657

In this section, we will explore what CVE-2022-39218 is, its impact, technical details, mitigation, and prevention steps.

What is CVE-2022-20657?

The JS Compute Runtime for Fastly's Compute@Edge platform has a vulnerability in versions prior to 0.5.3 where

Math.random

and

crypto.getRandomValues

methods use fixed seeds, making random values predictable. Attackers can exploit this to bypass security controls.

The Impact of CVE-2022-20657

The vulnerability in CVE-2022-39218 has a high severity base score of 7.5, with a high impact on confidentiality. It allows attackers to predict random numbers and potentially disclose encrypted sensitive data.

Technical Details of CVE-2022-20657

Let's delve into the technical aspects of this vulnerability.

Vulnerability Description

In versions below 0.5.3, the fixed seed in

Math.random

and

crypto.getRandomValues

methods leads to predictable random values, enabling attackers to bypass security measures.

Affected Systems and Versions

The vulnerability affects the js-compute-runtime versions earlier than 0.5.3 used in Fastly's Compute@Edge platform.

Exploitation Mechanism

Attackers can utilize the fixed seed in the PRNG to predict random numbers generated by

Math.random

and

crypto.getRandomValues

, compromising cryptographic security controls.

Mitigation and Prevention

Here are the steps to mitigate the risks associated with CVE-2022-39218.

Immediate Steps to Take

Upgrade to version 0.5.3 of js-compute-runtime to patch the vulnerability and prevent exploitation. Avoid using affected versions to protect sensitive data.

Long-Term Security Practices

Implement secure coding practices, conduct regular security audits, and stay informed about security updates to prevent future vulnerabilities.

Patching and Updates

Stay informed about security advisories from Fastly and promptly apply patches to ensure your system is protected against known vulnerabilities.