In this post, we'll delve deep into the command injection vulnerability discovered in the Git package, specifically in versions before 1.11.. The vulnerability, allocated as CVE-2022-25648, can lead to arbitrary code execution via git argument injection. We'll also look at the impact, code snippets, and potential solutions to mitigate this issue.

Exploit Details

The vulnerability revolves around the fetch(remote = 'origin', opts = {}) function in the Git package. Parameters supplied via "remote" argument are passed to the "git fetch" subcommand, which can be manipulated to accept additional flags. An attacker can exploit these additional flags to inject commands, leading to arbitrary code execution.

Here's a code snippet demonstrating the vulnerable function

def fetch(remote='origin', opts={}):
    command = ['git', 'fetch', remote]
    for opt, value in opts.items():
        command += [opt, value]
    return subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)

In the snippet above, the "remote" parameter is passed to the "git fetch" subcommand without proper sanitization or escaping, allowing potential malicious input.

To illustrate this exploit in action, let's consider the following example

remote = "origin; touch /tmp/payload;"
opts = {}

fetch(remote, opts)

In this scenario, payload is set to "origin; touch /tmp/payload;". By calling the "fetch()" function, it would execute the "git fetch" command alongside the code that follows the semicolon in the string. In this case, it would create a new empty file named "payload" in the "/tmp" directory.

It's crucial to note that affected versions of the Git package are those prior to 1.11.. Consequently, updating to the latest version will effectively mitigate this vulnerability.

Original References

- CVE Details:
- Git Security Advisory:
- GitHub Issue:


To address this issue, upgrade to the latest version of the Git package or apply security patches provided by the maintainer. You can update to the latest version using the respective package manager for your system:

# For Ubuntu based systems
sudo apt-get update
sudo apt-get upgrade git

# For CentOS/RHEL systems
sudo yum update git

In addition, it's necessary to sanitize user inputs to ensure that they don't include unexpected or malicious characters. A popular approach is to use a allow-list of valid characters or escape any potentially dangerous characters before passing them to the command.

Here's an updated version of the "fetch()" function using Python's shlex.quote() to safely escape arguments:

import shlex

def fetch_secure(remote='origin', opts={}):
    command = ['git', 'fetch', shlex.quote(remote)]  # Safely escape the "remote" argument
    for opt, value in opts.items():
        command += [shlex.quote(opt), shlex.quote(value)]  # Safely escape the "opt" and "value" arguments
    return subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)

By implementing these measures, users can rest assured that their systems are safeguarded from the CVE-2022-25648 vulnerability.

In conclusion, it's essential to stay informed and attentive to security vulnerabilities such as CVE-2022-25648. By understanding the risks, how they can be exploited, and applying appropriate mitigations, developers can better protect their applications and user data from potential threats.


Published on: 04/19/2022 17:15:00 UTC
Last modified on: 06/02/2022 14:15:00 UTC