CVE-2021-26700 in Visual Studio Code
Summary
by MITRE • 02/26/2021
Visual Studio Code npm-script Extension Remote Code Execution Vulnerability
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Analysis
by VulDB Data Team • 07/16/2025
The CVE-2021-26700 vulnerability represents a critical remote code execution flaw within the Visual Studio Code npm-script extension that affects developers working with node.js projects. This vulnerability stems from insufficient input validation in the extension's handling of npm script execution commands, creating a pathway for malicious actors to execute arbitrary code on vulnerable systems. The issue specifically impacts users who utilize the npm-script extension for managing package scripts within their development environments, making it particularly dangerous in corporate development workflows where multiple developers collaborate on projects.
The technical root cause of this vulnerability lies in the extension's failure to properly sanitize user inputs when processing npm script commands. When developers configure or execute npm scripts through the Visual Studio Code interface, the extension does not adequately validate the command parameters before passing them to the underlying npm execution engine. This lack of input sanitization creates a classic command injection vulnerability that can be exploited by attackers who craft malicious script definitions or manipulate existing script configurations. The vulnerability operates at the intersection of improper input validation and insufficient output encoding, aligning with CWE-77 and CWE-89 categories that address command injection and SQL injection respectively.
The operational impact of CVE-2021-26700 extends beyond individual developer machines to potentially compromise entire development environments and CI/CD pipelines. Attackers can leverage this vulnerability to execute malicious code with the privileges of the user running Visual Studio Code, potentially leading to data exfiltration, system compromise, or further network infiltration. The vulnerability is particularly concerning because it targets development tools that are frequently used in enterprise environments, where the compromise of a single developer's machine could provide attackers with access to source code repositories, development credentials, and potentially production systems. The attack surface is broad as the vulnerability affects any environment where Visual Studio Code with the npm-script extension is installed and used for npm script execution.
Mitigation strategies for CVE-2021-26700 should prioritize immediate patching of the affected npm-script extension to the latest version that addresses the input validation issues. Organizations should implement strict access controls and network segmentation to limit the potential impact of exploitation, ensuring that Visual Studio Code installations are not directly exposed to untrusted networks. Security teams should conduct comprehensive vulnerability assessments of all development environments to identify systems running the vulnerable extension, while also implementing monitoring solutions to detect suspicious script execution patterns. Additionally, developers should be educated about the risks of executing untrusted npm scripts and encouraged to validate script contents before execution. The remediation process should also include reviewing and hardening the configuration of npm scripts to minimize the attack surface, as outlined in the ATT&CK framework's methodology for defending against command injection techniques. Organizations should maintain updated threat intelligence feeds to monitor for exploitation attempts targeting this vulnerability and ensure that all development tools are kept current with security patches.