Arbitrary File Write via Archive Extraction (Zip Slip) Affecting dotnetzip package, versions [,1.11.0)


Severity

Recommended
0.0
medium
0
10

CVSS assessment made by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.14% (51st percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-DOTNET-DOTNETZIP-60245
  • published31 May 2018
  • disclosed17 Apr 2018
  • creditSnyk Security research Team

Introduced: 17 Apr 2018

CVE-2018-1002205  (opens in a new tab)
CWE-29  (opens in a new tab)
First added by Snyk

How to fix?

Upgrade dotnetzip to version 1.11.0 or higher.

Overview

dotnetzip is a class library and toolset for manipulating zip files.

Affected versions of the package are vulnerable to Arbitrary File Write via Archive Extraction (AKA "Zip Slip").

It is exploited using a specially crafted zip archive, that holds path traversal filenames. When exploited, a filename in a malicious archive is concatenated to the target extraction directory, which results in the final path ending up outside of the target folder. For instance, a zip may hold a file with a "../../file.exe" location and thus break out of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.

The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicous file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:


+2018-04-15 22:04:29 ..... 19 19 good.txt

+2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys

CVSS Scores

version 3.1