Is CVE-2021-39134 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2021-39134 being exploited in the wild.

How severe is CVE-2021-39134?

Low severity, with a CVSS score of 3.1, published 31 August 2021.

Which products and versions are affected?

@npmcli/arborist (npm) SEMVER:introduced=0,fixed=2.8.2; Arborist (npm) < 2.8.2; npm (npm) < 2.8.2.

Is there a fix for CVE-2021-39134?

Yes. @npmcli/arborist (npm): upgrade to 2.8.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2021-39134 attacked?

It is attacked with local access, in a software library.

Am I affected by CVE-2021-39134?

Check whether you run @npmcli/arborist (npm), Arborist (npm) or npm (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2021-39134: npm Arborist symlink following on case-insensitive filesystems

Q: Is there a fix for CVE-2021-39134?

Yes. @npmcli/arborist (npm): upgrade to 2.8.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2021-39134 attacked?

It is attacked with local access, in a software library.

Q: Am I affected by CVE-2021-39134?

Check whether you run @npmcli/arborist (npm), Arborist (npm) or npm (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2021-39134 · Severity: low · CVSS 3.1 · Published 2021-08-31

A vulnerability in the npm package manager's dependency management library could allow a malicious package to overwrite files on a user's computer. This occurs on systems with case-insensitive file systems, such as Windows and macOS, when a package uses specially crafted names and symbolic links. An attacker could use this to gain unauthorized access to data or execute malicious code when a user installs a compromised package.

Technologies: npm (npm). Vendors: npm.

Quick answers

Is CVE-2021-39134 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2021-39134 being exploited in the wild.
How severe is CVE-2021-39134?: Low severity, with a CVSS score of 3.1, published 31 August 2021.
Which products and versions are affected?: @npmcli/arborist (npm) SEMVER:introduced=0,fixed=2.8.2; Arborist (npm) < 2.8.2; npm (npm) < 2.8.2.
Is there a fix for CVE-2021-39134?: Yes. @npmcli/arborist (npm): upgrade to 2.8.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2021-39134 attacked?: It is attacked with local access, in a software library.
Am I affected by CVE-2021-39134?: Check whether you run @npmcli/arborist (npm), Arborist (npm) or npm (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

@npmcli/arborist (npm): upgrade to 2.8.2 or later
```
npm install @npmcli/arborist@2.8.2
```

Technical details

A vulnerability exists in @npmcli/arborist, the library used by npm to manage node_modules, due to improper handling of case sensitivity and symbolic links (CWE-178, CWE-61). On case-insensitive filesystems (macOS/Windows), Arborist's internal data structures treated dependencies with names differing only by case as distinct entities. An attacker can exploit this by creating a package with a symlink dependency (e.g., 'foo') pointing to a sensitive system path, followed by another dependency with a case-variant name (e.g., 'FOO'). During installation, the second package's contents are extracted through the symlink, resulting in arbitrary file overwrite or creation. This is fixed in @npmcli/arborist 2.8.2 and npm 7.20.7.

Affected products

npm @npmcli/arborist < 2.8.2
npm npm < 7.20.7

Identifiers

CVE-2021-39134
GHSA-2h3h-q99f-3fhc

Timeline

2021-08-31: disclosed
2021-08-31: advisory
2021-08-31: patched

References

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