Arbitrary File Write Affecting tar package, versions >=6.0.0 <6.1.9 >=5.0.0 <5.0.10 <4.4.18


Severity

Recommended
0.0
high
0
10

CVSS assessment made by Snyk's Security Team

    Threat Intelligence

    EPSS
    0.13% (49th percentile)

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  • Snyk ID SNYK-JS-TAR-1579152
  • published 1 Sep 2021
  • disclosed 1 Sep 2021
  • credit ginkoid, chen-robert, JarLob

How to fix?

Upgrade tar to version 6.1.9, 5.0.10, 4.4.18 or higher.

Overview

tar is a full-featured Tar for Node.js.

Affected versions of this package are vulnerable to Arbitrary File Write. 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 is insufficient when extracting tar files that contain two directories and a symlink with names containing unicode values that normalized to the same value. Additionally, on Windows systems, long path portions would resolve to the same file system entities as their 8.3 "short path" counterparts. A specially crafted tar archive can include directories with two forms of the path that resolve to the same file system entity, followed by a symbolic link with a name in the first form, lastly followed by a file using the second form. This leads to bypassing node-tar symlink checks on directories, essentially allowing an untrusted tar file to symlink into an arbitrary location and extracting arbitrary files into that location.

References

CVSS Scores

version 3.1
Expand this section

Snyk

Recommended
8.5 high
  • Attack Vector (AV)
    Local
  • Attack Complexity (AC)
    Low
  • Privileges Required (PR)
    None
  • User Interaction (UI)
    Required
  • Scope (S)
    Changed
  • Confidentiality (C)
    High
  • Integrity (I)
    High
  • Availability (A)
    Low
Expand this section

NVD

8.6 high
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SUSE

8.1 high
Expand this section

Red Hat

8.1 high