CVE-2021-37713 | Arbitrary File Creation/Overwrite on Windows via insufficient relative path sanitization

The npm package "tar" (aka node-tar) before versions 4.4.18, 5.0.10, and 6.1.9 has an arbitrary file creation/overwrite and arbitrary code execution vulnerability. node-tar aims to guarantee that any file whose location would be outside of the extraction target directory is not extracted. This is, in part, accomplished by sanitizing absolute paths of entries within the archive, skipping archive entries that contain `..` path portions, and resolving the sanitized paths against the extraction target directory. This logic was insufficient on Windows systems when extracting tar files that contained a path that was not an absolute path, but specified a drive letter different from the extraction target, such as `C:some\path`. If the drive letter does not match the extraction target, for example `D:\extraction\dir`, then the result of `path.resolve(extractionDirectory, entryPath)` would resolve against the current working directory on the `C:` drive, rather than the extraction target directory. Additionally, a `..` portion of the path could occur immediately after the drive letter, such as `C:../foo`, and was not properly sanitized by the logic that checked for `..` within the normalized and split portions of the path. This only affects users of `node-tar` on Windows systems. These issues were addressed in releases 4.4.18, 5.0.10 and 6.1.9. The v3 branch of node-tar has been deprecated and did not receive patches for these issues. If you are still using a v3 release we recommend you update to a more recent version of node-tar. There is no reasonable way to work around this issue without performing the same path normalization procedures that node-tar now does. Users are encouraged to upgrade to the latest patched versions of node-tar, rather than attempt to sanitize paths themselves.

Published: 2021-08-31 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-37713 is rated Moderate Risk (51.5/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.32%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-37713

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-03 0.61% 0.32% -0.29%
2 2025-09-14 0.82% 0.61% -0.21%
3 2025-09-12 0.82%

Full EPSS history (15 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-37713

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.2 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
1.8 5.8 [email protected]
8.6 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.8 6.0 [email protected]
4.4 2.0 MEDIUM
AV:L/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
3.4 6.4 [email protected]

Weakness enumeration for CVE-2021-37713

GitHub Security Advisory for CVE-2021-37713

GHSA-5955-9wpr-37jh · Severity: high · Ecosystem: npm — Arbitrary File Creation/Overwrite on Windows via insufficient relative path sanitization

OS Trackers for CVE-2021-37713

vendor priority summary link
alpine high CVE-2021-37713: 1 source package rows (nodejs); 9 state rows across 9 repos (3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 9, open 0. https://security.alpinelinux.org/vuln/CVE-2021-37713
debian unimportant CVE-2021-37713 unimportant priority: Debian including 1 source packages (node-tar), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-37713
redhat https://access.redhat.com/security/cve/CVE-2021-37713
suse high CVE-2021-37713 severity important: SUSE including 36 source package names (12-10.1:nodejs12-12.22.7-4.22.1, 12-10.1:npm12-12.22.7-4.22.1, …), 88 product×package rows across 11 product lines (Container bci/nodejs, SUSE Linux Enterprise Module for Open Buildservice Development Tools 15 SP4, … (11 product lines)): Fixed 80, Known Not Affected 8. https://www.suse.com/security/cve/CVE-2021-37713/
ubuntu medium CVE-2021-37713 medium priority: Ubuntu including 1 source packages (node-tar), 12 status rows across 12 suites (bionic, focal, hirsute, impish, jammy, kinetic, lunar, mantic, noble, trusty, upstream, xenial): not-affected 7, ignored 5. https://ubuntu.com/security/CVE-2021-37713

Affected software / configurations for CVE-2021-37713

Vendor Product Version Raw CPE
npmjs tar < 4.4.18 cpe:2.3:a:npmjs:tar:*:*:*:*:*:node.js:*:*
npmjs tar >= 5.0.0, < 5.0.10 cpe:2.3:a:npmjs:tar:*:*:*:*:*:node.js:*:*
npmjs tar >= 6.0.0, < 6.1.9 cpe:2.3:a:npmjs:tar:*:*:*:*:*:node.js:*:*
oracle graalvm 20.3.3 cpe:2.3:a:oracle:graalvm:20.3.3:*:*:*:enterprise:*:*:*
oracle graalvm 21.2.0 cpe:2.3:a:oracle:graalvm:21.2.0:*:*:*:enterprise:*:*:*
siemens sinec_infrastructure_network_services < 1.0.1.1 cpe:2.3:a:siemens:sinec_infrastructure_network_services:*:*:*:*:*:*:*:*

References for CVE-2021-37713

cvelogic Threat Intelligence