External Control of System or Configuration Setting Affecting in-toto package, versions [,2.0.0)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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-PYTHON-INTOTO-5529846
- published12 May 2023
- disclosed11 May 2023
- creditUnknown
Introduced: 11 May 2023
CVE-2023-32076 (opens in a new tab)How to fix?
Upgrade in-toto to version 2.0.0 or higher.
Overview
in-toto is a framework to define and secure the integrity of software supply chains
Affected versions of this package are vulnerable to External Control of System or Configuration Setting. The in-toto configuration is read from various directories and allows users to configure the behavior of the framework. The files are from directories following the XDG base directory specification. Among the files read is .in_totorc which is a hidden file in the directory in which in-toto is run. If an attacker controls the inputs to a supply chain step, they can mask their activities by also passing in an .in_totorc file that includes the necessary exclude patterns and settings.
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