tarproject tar CVE-2021-32804 vulnerability in Tarproject and Other Products
Published on August 3, 2021

Arbitrary File Creation/Overwrite due to insufficient absolute path sanitization

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The npm package "tar" (aka node-tar) before versions 6.1.1, 5.0.6, 4.4.14, and 3.3.2 has a arbitrary File Creation/Overwrite vulnerability due to insufficient absolute path sanitization. node-tar aims to prevent extraction of absolute file paths by turning absolute paths into relative paths when the `preservePaths` flag is not set to `true`. This is achieved by stripping the absolute path root from any absolute file paths contained in a tar file. For example `/home/user/.bashrc` would turn into `home/user/.bashrc`. This logic was insufficient when file paths contained repeated path roots such as `////home/user/.bashrc`. `node-tar` would only strip a single path root from such paths. When given an absolute file path with repeating path roots, the resulting path (e.g. `///home/user/.bashrc`) would still resolve to an absolute path, thus allowing arbitrary file creation and overwrite. This issue was addressed in releases 3.2.2, 4.4.14, 5.0.6 and 6.1.1. Users may work around this vulnerability without upgrading by creating a custom `onentry` method which sanitizes the `entry.path` or a `filter` method which removes entries with absolute paths. See referenced GitHub Advisory for details. Be aware of CVE-2021-32803 which fixes a similar bug in later versions of tar.

Github Repository NVD

Vulnerability Analysis

CVE-2021-32804 is exploitable with local system access, requires user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and no impact on availability.

Attack Vector:
LOCAL
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
REQUIRED
Scope:
CHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
NONE

Weakness Type

What is a Directory traversal Vulnerability?

The software uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the software does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

CVE-2021-32804 has been classified to as a Directory traversal vulnerability or weakness.


Products Associated with CVE-2021-32804

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2021-32804 are published in these products:

Tarproject Tar
 
Oracle GraalVM
 
Siemens Sinec Infrastructure Network Services
 

Affected Versions

npm node-tar:

Vulnerable Packages

The following package name and versions may be associated with CVE-2021-32804

Package Manager Vulnerable Package Versions Fixed In
npm tar >= 6.0.0, < 6.1.1 6.1.1
npm tar >= 5.0.0, < 5.0.6 5.0.6
npm tar >= 4.0.0, < 4.4.14 4.4.14
npm tar < 3.2.2 3.2.2

Exploit Probability

EPSS
84.98%
Percentile
99.34%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.