CVE-2021-391358.2HighCWE-61

CVE-2021-39135: UNIX Symbolic Link (Symlink) Following in @npmcli/arborist

npm · arborist

Affected: npm arborist · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.6%probability of exploitation in the next 30 days

47th percentile

050100

Higher than 47% of scored CVEs

8.2HighCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

`@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 install --ignore-scripts` in the root. This may be successful, because `npm install --ignore-scripts` is typically not capable of making changes outside of the project directory, so it may be deemed safe. This is patched in @npmcli/arborist 2.8.2 which is included in npm v7.20.7 and above. For more information including workarounds please see the referenced GHSA-gmw6-94gg-2rc2.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

npm · arborist< 2.8.2

On the Atlas

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Open the Atlas

Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: UNIX Symbolic Link (Symlink) Following · File and Path Handling
Vendor: npm
Published: August 2021
Band: Unlikely (under 1%), August 2021

CoverageNo articles yet

No CyberSIXT article names CVE-2021-39135 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.