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CVE-2021-39135

8.2 · HIGH
Published Aug 31, 2021 npmjs CWE-61 EPSS 0.55% (44th pctl)

Overview

CVE-2021-39135 is a high-severity vulnerability affecting npmjs arborist. It was published on August 31, 2021 and has a CVSS 3.1 base score of 8.2 (HIGH).

This vulnerability has a CVSS 3.1 base score of 8.2, rated HIGH. It requires local or adjacent network access to exploit. No authentication or special privileges are required for exploitation.

Technical Description

`@npmcli/arborist`, the library that calculates dependency trees and manages the node_modules folder hierarchy for the npm command line interface, aims to guarantee that package dependency contracts will be met, and the extraction of package contents will always be performed into the expected folder. This is accomplished by extracting package contents into a project's `node_modules` folder. If the `node_modules` folder of the root project or any of its dependencies is somehow replaced with a symbolic link, it could allow Arborist to write package dependencies to any arbitrary location on the file system. Note that symbolic links contained within package artifact contents are filtered out, so another means of creating a `node_modules` symbolic link would have to be employed. 1. A `preinstall` script could replace `node_modules` with a symlink. (This is prevented by using `--ignore-scripts`.) 2. An attacker could supply the target with a git repository, instructing them to run `npm insta

Remediation

Check the references section for vendor advisories and patches from npmjs. Update arborist to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

Vendor Product Versions Status
npmjs arborist >= 0, < 2.8.2 Affected
npmjs npm >= 0, < 7.20.7 Affected
siemens sinec_infrastructure_network_services >= 0, < 1.0.1.1 Affected

Frequently Asked Questions

What is CVE-2021-39135?

CVE-2021-39135 is a high-severity vulnerability affecting npmjs arborist. It was published on August 31, 2021 and has a CVSS 3.1 base score of 8.2 (HIGH).

How severe is CVE-2021-39135?

This vulnerability has a CVSS 3.1 base score of 8.2, rated HIGH. It requires local or adjacent network access to exploit. No authentication or special privileges are required for exploitation.

How do I fix or remediate CVE-2021-39135?

Check the references section for vendor advisories and patches from npmjs. Update arborist to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2021-39135?

CyberStrike's AI-powered security agents can automatically detect CVE-2021-39135 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.