CVE-2021-37713
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.
| Software | From | Fixed in |
|---|---|---|
| npmjs / tar | - | 4.4.18 |
| npmjs / tar | 5.0.0 | 5.0.10 |
| npmjs / tar | 6.0.0 | 6.1.9 |
| oracle / graalvm | 20.3.3 | 20.3.3.x |
| oracle / graalvm | 21.2.0 | 21.2.0.x |
| siemens / sinec_infrastructure_network_services | - | 1.0.1.1 |
tar
|
- | 4.4.18 |
|
tar
|
5.0.0 | 5.0.10 |
|
tar
|
6.0.0 | 6.1.9 |
- https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf
- https://github.com/isaacs/node-tar/commit/52b09e309bcae0c741a7eb79a17ef36e7828b946
- https://github.com/isaacs/node-tar/commit/82eac952f7c10765969ed464e549375854b26edc
- https://github.com/isaacs/node-tar/commit/875a37e3ec031186fc6599f6807341f56c584598
- https://github.com/npm/node-tar/security/advisories/GHSA-5955-9wpr-37jh
- https://www.npmjs.com/package/tar
- https://www.oracle.com/security-alerts/cpuoct2021.html
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A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
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Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.
Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.
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