CVE-2022-3861 - PHP Object Injection Vulnerability in Betheme WordPress Theme

An instance of PHP Object Injection (POI) vulnerability has been discovered within the Betheme theme for WordPress. This article will delve into the specifics of the vulnerability, how it can be exploited, and its potential consequences. The vulnerability, officially referred to as CVE-2022-3861, is present in Betheme versions up to and including 26.5.1.4. The ability to inject a PHP Object can lead to serious security implications, with potential access to sensitive data, code execution, or the deletion of files.

Vulnerability Details

The POI vulnerability in the Betheme WordPress theme is a result of the deserialization of untrusted input provided via the import, mfn-items-import-page, and mfn-items-import parameters. These parameters can be passed through the following functions:

importfromclipboard

The deserialization process occurs within these functions and could allow an authenticated attacker, with contributor-level permissions or higher, to inject a PHP Object into the application. Furthermore, the presence of a PHP Object Oriented Programming (POP) chain can enable the attacker to execute code, gain access to sensitive information, delete files, or conduct other malicious activities.

Below is a code snippet demonstrating the potential vulnerability

function mfn_builder_import($code) {
 ...
 $data = @unserialize(base64_decode($code));
 ...
}

mfn_builder_import($_GET['import']);

In this example, the import parameter is used to supply data to the unserialize and base64_decode functions, which are combined in the mfn_builder_import function. The deserialize process leads to potential POI.

Exploit Details

To exploit this vulnerability, an attacker would require contributor-level permissions or above, which significantly reduces the potential number of malicious users who could gain unauthorized access. Nonetheless, if an attacker can successfully obtain the required permissions, they could exploit the vulnerability through the use of a POP chain, which could enable them to execute code remotely or gain access to sensitive information.

The POP chain, typically consisting of various gadgets, can easily be crafted by an attacker to exploit the PHP Object deserialization, putting the integrity and security of the WordPress site in jeopardy.

Mitigation and Conclusion

To address this vulnerability, it is essential to update the Betheme WordPress theme to a version higher than 26.5.1.4. The developers have been made aware of the issue, and a patch has been released to resolve this vulnerability.

Original References

1. CVE-2022-3861 Official Details
2. Betheme WordPress Theme

In summary, CVE-2022-3861 represents a PHP Object Injection vulnerability within the Betheme theme for WordPress, potentially leading to unauthorized access, code execution, or unintended data exposure. It is crucial for users to stay informed about the latest updates and patches for their software to reduce the risk of their site falling victim to such exploits.

Timeline

Published on: 11/21/2022 13:15:00 UTC
Last modified on: 11/30/2022 15:31:00 UTC