Pimcore is a popular open-source data and experience management platform used by thousands of businesses and developers worldwide. A recent vulnerability in Pimcore, designated as CVE-2022-39365, has been discovered, which could lead to server-side template injection and potentially remote code execution.

This vulnerability affects Pimcore versions prior to 10.5.9. In this long read post, we'll delve into the details of this vulnerability, including code snippets, links to original references, and exploit details. We'll also discuss the patch included in version 10.5.9 and how you can apply it manually as a workaround.

Vulnerability Details

The critical vulnerability in Pimcore is caused by user-controlled Twig templates rendering in Pimcore\Mail and ClassDefinition\Layout\Text components. Twig is a flexible and secure templating engine that is designed to ensure the separation of application logic from the representation layer. However, in affected Pimcore versions, it is possible for an attacker to manipulate the template data, leading to server-side template injection.

This vulnerability is particularly concerning because it can potentially allow attackers to execute arbitrary code on the server, leading to unauthorized access, data exfiltration, and other malicious activities.

Here's a code snippet that demonstrates the vulnerable section of the codebase

$mail = new \Pimcore\Mail(['document' => $template, 'params' => $templateParams]);
$mail->addTo($user->getEmail());
$mail->send();

In this snippet, user-supplied inputs are used to determine the Twig template and parameters. By manipulating these inputs, an attacker could gain unauthorized access to the internals of the Twig engine and cause the server-side template injection.

Exploit Details

To exploit the CVE-2022-39365 vulnerability, an attacker needs to have a basic understanding of the Pimcore infrastructure and some level of access to the application. The attacker would have to supply malicious payloads to the affected components, injecting server-side templates that may lead to code execution.

For example, an attacker could craft a malicious payload like the following

{{ 'root:mySecureP4ss|' |template("plain") }}

In this payload, the attacker tries to inject a template that will execute shell commands on the server, potentially modifying sensitive files or gaining unauthorized access.

Patch and Workarounds

The Pimcore team has addressed the CVE-2022-39365 vulnerability by releasing a patch in version 10.5.9. Upgrading to this version is the recommended solution to protect your Pimcore installation against this vulnerability.

You can find the patch details in the official GitHub repository: Pimcore 10.5.9 Release

Locate the sections of code where user input is passed to the Twig template and parameters.

3. Modify the code to sanitize and validate user-supplied input before it's passed to the Twig engine, reducing the risk of server-side template injection.

However, it's essential to note that applying the patch manually might not provide the same level of protection as upgrading to the latest version.

Conclusion

The CVE-2022-39365 vulnerability in Pimcore poses a significant risk to businesses and developers who rely on this open-source platform. By understanding the nature of the vulnerability and applying the appropriate patches or upgrading to the latest version, you can mitigate the risks and ensure the security of your Pimcore-powered applications.

Remember always to keep your software up-to-date and follow best practices for secure development to minimize the chances of security vulnerabilities affecting your projects.

Timeline

Published on: 10/27/2022 15:15:00 UTC
Last modified on: 10/31/2022 14:13:00 UTC