CVE-2021-21353 : Security Advisory and Response

Pug is an npm package known for its high-performance template engine. This CVE highlights a vulnerability in Pug versions prior to 3.0.1, allowing a remote attacker to exploit the

pretty

option of the pug compiler, potentially leading to remote code execution on the node.js backend. The impact severity is rated as MEDIUM with a CVSS base score of 6.8.

Understanding CVE-2021-21353

This section delves into the details of the CVE, its impact, affected systems, and mitigation strategies.

What is CVE-2021-21353?

Pug, a popular npm package, was susceptible to remote code execution due to a flaw in versions before 3.0.1. Exploitation of the

pretty

option within the pug compiler could grant attackers control over the backend system.

The Impact of CVE-2021-21353

The vulnerability's severity is categorized as MEDIUM, with a CVSS base score of 6.8. Attackers could execute remote code on node.js backends, compromising the system's integrity.

Technical Details of CVE-2021-21353

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

Vulnerability Description

The flaw in Pug versions < 3.0.1 allowed remote attackers to achieve remote code execution by manipulating the

pretty

option in the pug compiler.

Affected Systems and Versions

Pug versions prior to 3.0.1, including the packages 'pug' and 'pug-code-gen', were impacted by this vulnerability.

Exploitation Mechanism

By controlling the

pretty

option in the pug compiler, attackers could inject malicious code to achieve remote code execution on the node.js backend.

Mitigation and Prevention

In this section, we discuss immediate steps to take, long-term security practices, and the importance of patching and updates.

Immediate Steps to Take

Users are advised to update Pug to version 3.0.1 to mitigate the risk of remote code execution. Avoid passing untrusted input through the

pretty

option.

Long-Term Security Practices

Implement input validation and sanitization procedures to prevent code injection attacks across your application's stack.

Patching and Updates

Regularly monitor for security advisories, update dependencies, and apply patches promptly to ensure ongoing protection against potential vulnerabilities.