CVE-2021-32804: The npm package "tar" (aka node-tar) before versions 6.1.1, 5.0.6, 4.4.14, and 3.3.2 has a arbitrary File Creation/Overwrite vulnerability due to insu...

Description

The npm package "tar" (aka node-tar) before versions 6.1.1, 5.0.6, 4.4.14, and 3.3.2 has a arbitrary File Creation/Overwrite vulnerability due to insufficient absolute path sanitization. node-tar aims to prevent extraction of absolute file paths by turning absolute paths into relative paths when the `preservePaths` flag is not set to `true`. This is achieved by stripping the absolute path root from any absolute file paths contained in a tar file. For example `/home/user/.bashrc` would turn into `home/user/.bashrc`. This logic was insufficient when file paths contained repeated path roots such as `////home/user/.bashrc`. `node-tar` would only strip a single path root from such paths. When given an absolute file path with repeating path roots, the resulting path (e.g. `///home/user/.bashrc`) would still resolve to an absolute path, thus allowing arbitrary file creation and overwrite. This issue was addressed in releases 3.2.2, 4.4.14, 5.0.6 and 6.1.1. Users may work around this vulnerability without upgrading by creating a custom `onentry` method which sanitizes the `entry.path` or a `filter` method which removes entries with absolute paths. See referenced GitHub Advisory for details. Be aware of CVE-2021-32803 which fixes a similar bug in later versions of tar.

Metrics

CVSS 3.1

8.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H

EPSS Probability

15.01%

96.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Tar Project	Tar	< 3.2.2
Tar Project	Tar	>= 4.0.0, < 4.4.14
Tar Project	Tar	>= 5.0.0, < 5.0.6
Tar Project	Tar	>= 6.0.0, < 6.1.1
Oracle	Graalvm	20.3.3
Oracle	Graalvm	21.2.0
Siemens	Sinec Infrastructure Network Services	< 1.0.1.1

References

https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdfPatch, Third Party Advisory
https://github.com/npm/node-tar/commit/1f036ca23f64a547bdd6c79c1a44bc62e8115da4Patch, Third Party Advisory
https://github.com/npm/node-tar/security/advisories/GHSA-3jfq-g458-7qm9Mitigation, Third Party Advisory
https://www.npmjs.com/advisories/1770Mitigation, Third Party Advisory
https://www.npmjs.com/package/tarProduct, Third Party Advisory
https://www.oracle.com/security-alerts/cpuoct2021.htmlPatch, Third Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdfPatch, Third Party Advisory
https://github.com/npm/node-tar/commit/1f036ca23f64a547bdd6c79c1a44bc62e8115da4Patch, Third Party Advisory
https://github.com/npm/node-tar/security/advisories/GHSA-3jfq-g458-7qm9Mitigation, Third Party Advisory
https://www.npmjs.com/advisories/1770Mitigation, Third Party Advisory
https://www.npmjs.com/package/tarProduct, Third Party Advisory
https://www.oracle.com/security-alerts/cpuoct2021.htmlPatch, Third Party Advisory

Timeline

Published: Aug 3, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-32804?

The npm package "tar" (aka node-tar) before versions 6.1.1, 5.0.6, 4.4.14, and 3.3.2 has a arbitrary File Creation/Overwrite vulnerability due to insufficient absolute path sanitization. node-tar aims to prevent extraction of absolute file paths by turning absolute paths into relative paths when the `preservePaths` flag is not set to `true`. This is achieved by stripping the absolute path root from any absolute file paths contained in a tar file. For example `/home/user/.bashrc` would turn into `home/user/.bashrc`. This logic was insufficient when file paths contained repeated path roots such as `////home/user/.bashrc`. `node-tar` would only strip a single path root from such paths. When given an absolute file path with repeating path roots, the resulting path (e.g. `///home/user/.bashrc`) would still resolve to an absolute path, thus allowing arbitrary file creation and overwrite. This issue was addressed in releases 3.2.2, 4.4.14, 5.0.6 and 6.1.1. Users may work around this vulnerability without upgrading by creating a custom `onentry` method which sanitizes the `entry.path` or a `filter` method which removes entries with absolute paths. See referenced GitHub Advisory for details. Be aware of CVE-2021-32803 which fixes a similar bug in later versions of tar.

How severe is CVE-2021-32804?

CVE-2021-32804 has a CVSS score of 8.1/10 (HIGH severity). The EPSS model estimates a 15.01% probability of exploitation in the next 30 days.

How do I fix CVE-2021-32804?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.