CVE-2021-32804 : Exploit Details and Defense Strategies

Arbitrary File Creation/Overwrite vulnerability in npm package "tar" (node-tar) before versions 6.1.1, 5.0.6, 4.4.14, and 3.3.2 due to inadequate absolute path sanitization. The vulnerability allows arbitrary file creation/overwrite, impacting confidentiality, integrity, and availability of the system.

Understanding CVE-2021-32804

This section provides a detailed overview of the CVE-2021-32804 vulnerability.

What is CVE-2021-32804?

The vulnerability in the npm package "tar" (node-tar) enables arbitrary file creation and overwrite due to insufficient absolute path sanitization. The issue resides in the handling of repeated path roots in absolute file paths, allowing malicious actors to bypass security mechanisms.

The Impact of CVE-2021-32804

The vulnerability has a high severity impact, affecting confidentiality, integrity, and availability of affected systems. Attackers can exploit this flaw to create/overwrite arbitrary files, potentially leading to unauthorized access and data manipulation.

Technical Details of CVE-2021-32804

This section delves into the technical aspects and specifics of CVE-2021-32804.

Vulnerability Description

The arbitrary File Creation/Overwrite vulnerability stems from the inadequate absolute path sanitization mechanism in node-tar before versions 6.1.1, 5.0.6, 4.4.14, and 3.3.2. It allows the resolution of repeated path roots in absolute file paths, leading to the creation/overwriting of files.

Affected Systems and Versions

node-tar versions < 3.2.2
node-tar versions >= 4.0.0, < 4.4.14
node-tar versions >= 5.0.0, < 5.0.6
node-tar versions >= 6.0.0, < 6.1.1

Exploitation Mechanism

Malicious actors can exploit the vulnerability by leveraging repeated path roots in absolute file paths to bypass path sanitization mechanisms, allowing them to create/overwrite arbitrary files.

Mitigation and Prevention

This section outlines the steps to mitigate and prevent exploitation of CVE-2021-32804.

Immediate Steps to Take

Users are advised to upgrade their node-tar packages to versions 3.2.2, 4.4.14, 5.0.6, or 6.1.1 to address the vulnerability. Alternatively, creating custom sanitization methods for entry paths can help mitigate the risk.

Long-Term Security Practices

Implement secure coding practices, perform regular security assessments, and stay informed about the latest security advisories to prevent similar vulnerabilities in the future.

Patching and Updates

Stay updated with the latest releases and security patches for node-tar to ensure that your systems are protected against known vulnerabilities.