Directory Traversal Affecting actionpack package, versions < 4.1.1, >= 4.1< 4.0.5, >= 3.3< 3.2.18


Severity

Recommended
0.0
high
0
10

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

Threat Intelligence

Exploit Maturity
Mature
EPSS
0.54% (78th percentile)

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  • Snyk IDSNYK-RUBY-ACTIONPACK-20158
  • published5 May 2014
  • disclosed5 May 2014
  • creditVille Lautanala

Introduced: 5 May 2014

CVE-2014-0130  (opens in a new tab)
CWE-22  (opens in a new tab)
First added by Snyk

How to fix?

Upgrade actionpack to version 3.2.18, 4.0.5, 4.1.1 or higher.

Overview

actionpack is a web app builder and tester on Rails.

Affected versions of this Gem are vulnerable to Directory Traversal attacks. The implicit render functionality allows controllers to render a template, even if there is no explicit action with the corresponding name. This module does not perform adequate input sanitization, which could allow an attacker to use a specially crafted request to retrieve arbitrary files from the rails application server.

Details

A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.

Directory Traversal vulnerabilities can be generally divided into two types:

  • Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.

st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.

If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.

curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa

Note %2e is the URL encoded version of . (dot).

  • Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as Zip-Slip.

One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside 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 malicious 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

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