Hello everyone!

Today, we're going to delve into a code injection vulnerability (CVE-2022-45908) that affects machine learning and deep learning framework PaddlePaddle. This vulnerability has been identified in versions of PaddlePaddle before 2.4. It particularly targets the paddle.audio.functional.get_window function, enabling malicious actors to execute arbitrary code. Let's explore this vulnerability in detail to see how it works, along with the exploit details and prevention techniques.

Vulnerability Description

PaddlePaddle is a popular open-source deep learning framework developed by Baidu. The specific vulnerability in the paddle.audio.functional.get_window function of PaddlePaddle allows code injection by utilizing the eval() function on a user-supplied winstr (window string). This can lead to arbitrary code execution with the privileges of the user running the PaddlePaddle service.

Code Snippet Highlighting the Issue

Let's take a look at the problematic code snippet in PaddlePaddle's paddle.audio.functional.get_window function:

def get_window(name, length, dtype='float32'):
    ...
    if name == 'kaiser' and not beta:
        raise ValueError('The "kaiser" window requires a beta parameter.')
    try:
        params = (length,) + tuple(beta)
        winfunc = eval('_' + name)
        window = winfunc(*params)  # eval call on winfunc, user-supplied name
    ...

In the above code snippet, the user-supplied name is used to construct a string that is later passed as an argument to the eval() function. If an attacker can control the name parameter, they could potentially craft a string to inject and execute malicious code.

Exploit Details

To exploit this vulnerability, an attacker would need to craft a specially formatted input string (winstr) and pass it to the paddle.audio.functional.get_window function. Let's take an example payload:

payload = "name='hamming'; __import__('os').system('touch exploit_successful')"

The above payload, when passed as input, would result in the touch exploit_successful command being executed, creating a file called "exploit_successful" in the current working directory (as an example of arbitrary code execution). Of course, this is just a harmless example; in reality, an attacker could potentially execute far more nefarious commands.

* CVE-2022-45908 - NIST National Vulnerability Database (NVD) Entry
* PaddlePaddle repository: https://github.com/PaddlePaddle/Paddle
* PaddlePaddle API documentation: paddle.audio.functional.get_window

Recommendations and Mitigation

To protect your PaddlePaddle applications from this vulnerability, the most effective solution is to upgrade PaddlePaddle to the latest version, as it has patched this specific vulnerability.

Always ensure the use of the latest, most secure version of software packages and regularly apply security patches and updates.

In addition to this, when using PaddlePaddle in your applications, consider validating, escaping, or sanitizing user input and avoiding the use of dangerous functions such as eval().

By following these best practices and keeping your software up-to-date, you can significantly reduce the risk of falling victim to vulnerabilities like CVE-2022-45908. Stay safe and keep your applications secure!

Timeline

Published on: 11/26/2022 02:15:00 UTC
Last modified on: 12/01/2022 17:59:00 UTC