CVE-2021-39208 : Security Advisory and Response

SharpCompress is a C# library for handling compression types. Versions under 0.29.0 are vulnerable to partial path traversal.

Understanding CVE-2021-39208

SharpCompress library versions below 0.29.0 are susceptible to a partial path traversal issue due to an incomplete validation of fullDestinationDirectoryPath.

What is CVE-2021-39208?

The vulnerability in SharpCompress versions before 0.29.0 allows for arbitrary file creation due to inadequate validation of the destination directory path.

The Impact of CVE-2021-39208

This vulnerability has a CVSS base score of 4.3, with a medium severity rating. The attack complexity is low, and integrity impact is rated as low.

Technical Details of CVE-2021-39208

The technical aspects of the vulnerability provide insight into its nature and implications.

Vulnerability Description

SharpCompress prior to version 0.29.0 permits partial path traversal, potentially leading to unauthorized file creation outside the intended directory.

Affected Systems and Versions

Product: sharpcompress
Vendor: adamhathcock
Vulnerable Versions: < 0.29.0

Exploitation Mechanism

The issue arises from an insufficiently validated destination path, allowing the creation of files in unintended locations.

Mitigation and Prevention

Steps to secure systems and prevent exploitation of the identified vulnerability.

Immediate Steps to Take

Upgrade to SharpCompress version 0.29.0 or higher to eliminate the vulnerability.
Verify directory paths and ensure they adhere to proper conventions.

Long-Term Security Practices

Regularly update software libraries to the latest secure versions.
Conduct security audits to identify and address similar vulnerabilities proactively.

Patching and Updates

Apply patches and updates provided by SharpCompress to remediate the path traversal vulnerability.