CVE-2023-33966 Explained : Impact and Mitigation

A vulnerability has been discovered in Deno, a runtime for JavaScript and TypeScript. This CVE highlights a missing "--allow-net" permission check for built-in Node modules in Deno versions 1.34.0 and deno_runtime 0.114.0. The issue has a base score of 8.6, classified as HIGH severity due to improper privilege management.

Understanding CVE-2023-33966

This section delves into the details of the CVE, its impact, technical aspects, and mitigation strategies.

What is CVE-2023-33966?

Deno 1.34.0 and deno_runtime 0.114.0 do not properly check outbound HTTP requests made using the built-in

node:http

or

node:https

modules against the network permission allow list (

--allow-net

). This vulnerability extends to dependencies relying on these modules, posing a risk to data integrity.

The Impact of CVE-2023-33966

Users of Deno versions prior to 1.34.0 and Deno Deploy remain unaffected. However, for those using affected versions, there is a risk of unauthorized outbound HTTP requests due to the missing permission check. The base score of 8.6 signifies a significant threat to data integrity.

Technical Details of CVE-2023-33966

This section outlines the vulnerability description, affected systems and versions, as well as the exploitation mechanism.

Vulnerability Description

The vulnerability arises from the absence of proper validation for outbound HTTP requests made using built-in Node modules in Deno versions 1.34.0 and deno_runtime 0.114.0. This oversight grants attackers the ability to bypass network permission restrictions.

Affected Systems and Versions

Vendor: denoland
Product: Deno
Affected Versions: Deno = 1.34.0, deno_runtime = 0.114.0

Exploitation Mechanism

Attackers can leverage this vulnerability to initiate unauthorized outbound HTTP requests using the affected built-in modules without being restricted by the network permission allow list (

--allow-net

), potentially compromising data integrity.

Mitigation and Prevention

To mitigate the risks associated with CVE-2023-33966, immediate steps, long-term security practices, and the importance of patching and updates are crucial.

Immediate Steps to Take

All users are recommended to update their Deno installations to version 1.34.1 and deno_runtime 0.114.1 to address the vulnerability. It is essential to apply these patches promptly to prevent unauthorized outbound HTTP requests.

Long-Term Security Practices

Incorporating proper privilege management practices, conducting regular security audits, and staying informed about software vulnerabilities are key to enhancing long-term security posture.

Patching and Updates

Regularly updating software, especially in response to security patches, is vital to protect against known vulnerabilities. Timely installation of patches ensures that systems are equipped with the latest security enhancements and bug fixes.