Arbitrary File Write

Affecting tar package, versions >=6.0.0 <6.1.9 || >=5.0.0 <5.0.10 || <4.4.18

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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 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 is insufficient on Windows systems when extracting tar files that contain a path that is not an absolute path, but specify 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) resolves against the current working directory on the C: drive, rather than the extraction target directory.

Additionally, a .. portion of the path can occur immediately after the drive letter, such as C:../foo, and is not properly sanitized by the logic that checks for .. within the normalized and split portions of the path.

Note: This only affects users of node-tar on Windows systems.

Remediation

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

References

CVSS Score

8.5
high severity
  • Attack Vector
    Local
  • Attack Complexity
    Low
  • Privileges Required
    None
  • User Interaction
    Required
  • Scope
    Changed
  • Confidentiality
    High
  • Integrity
    High
  • Availability
    Low
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L
Credit
ginkoid, chen-robert, JarLob
CVE
CVE-2021-37713
CWE
CWE-22
Snyk ID
SNYK-JS-TAR-1579155
Disclosed
01 Sep, 2021
Published
01 Sep, 2021