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High severity8.2NVD Advisory· Published Aug 3, 2021· Updated Jun 17, 2026

CVE-2021-32803

CVE-2021-32803

Description

The npm package "tar" (aka node-tar) before versions 6.1.2, 5.0.7, 4.4.15, and 3.2.3 has an arbitrary File Creation/Overwrite vulnerability via insufficient symlink protection. node-tar aims to guarantee that any file whose location would be modified by a symbolic link is not extracted. This is, in part, achieved by ensuring that extracted directories are not symlinks. Additionally, in order to prevent unnecessary stat calls to determine whether a given path is a directory, paths are cached when directories are created. This logic was insufficient when extracting tar files that contained both a directory and a symlink with the same name as the directory. This order of operations resulted in the directory being created and added to the node-tar directory cache. When a directory is present in the directory cache, subsequent calls to mkdir for that directory are skipped. However, this is also where node-tar checks for symlinks occur. By first creating a directory, and then replacing that directory with a symlink, it was thus possible to bypass node-tar symlink checks on directories, essentially allowing an untrusted tar file to symlink into an arbitrary location and subsequently extracting arbitrary files into that location, thus allowing arbitrary file creation and overwrite. This issue was addressed in releases 3.2.3, 4.4.15, 5.0.7 and 6.1.2.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Affected packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
tarnpm
>= 3.0.0, < 3.2.33.2.3
tarnpm
>= 4.0.0, < 4.4.154.4.15
tarnpm
>= 5.0.0, < 5.0.75.0.7
tarnpm
>= 6.0.0, < 6.1.26.1.2

Affected products

98

Patches

Vulnerability mechanics

References

12

News mentions

1