CVE-2022-3834: Stored Cross-Site Scripting Vulnerability in Google Forms WordPress Plugin Up to Version .95

A recent security vulnerability has been identified in the Google Forms WordPress plugin (up to version .95), which could allow high privilege users, such as an admin, to perform Stored Cross-Site Scripting (XSS) attacks even when the unfiltered_html capability is disallowed (for example, in a multisite setup). This blog post aims to provide a comprehensive insight into the details of this vulnerability, complete with code snippets and references to the original sources.

Details of the Vulnerability (CVE-2022-3834)

The Google Forms WordPress plugin, which enables users to create and manage Google Forms directly from their WordPress dashboard, is susceptible to a Stored Cross-Site Scripting attack. Essentially, the plugin fails to properly sanitize and escape certain settings, which opens up the possibility for malicious users with high privileges, such as admin, to inject harmful JavaScript code into the plugin settings. When these settings are viewed or interacted with, anyone visiting the site - including lower-privilege users - could be exposed to the injected code.

Code Snippet

The issue can be traced back to a lack of escaping and sanitization in some of the plugin settings. Below is an example of where this vulnerability occurs:

// In the file google-forms/admin/partials/section-render.php
$public_api_key = get_option( 'google_forms_public_api_key', '' );

In this snippet, the 'google_forms_public_api_key' setting should be sanitized and escaped. However, it is not, which means that harmful JavaScript code could potentially be inserted into this setting.

Exploit

To exploit this vulnerability, an attacker would need to have high-level admin access to a WordPress site that utilized the vulnerable Google Forms plugin. The attacker could then modify the plugin settings to include malicious JavaScript code, as demonstrated below:

javascript:alert('XSS')

When another user with lower privileges views or interacts with the affected settings, the injected JavaScript code would execute on their device, potentially compromising their account or the site itself.

Links to Original References

- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-3834
- https://github.com/ankitpokhrel/google-forms/security/advisories/GHSA-9phv-q37j-crfw

Mitigation and Recommendations

The simplest solution for mitigating this vulnerability is to update the Google Forms plugin to the latest version. If you are currently using version .95 or earlier, it is highly recommended that you update as soon as possible to protect your site and its users.

Additionally, it is essential to maintain proper access control and limit admin privileges to trusted users, as this vulnerability specifically targets high-privilege users within a multisite setup.

Conclusion

The CVE-2022-3834 vulnerability found in the Google Forms WordPress plugin (up to version .95) presents a serious security concern for website owners and users. This Stored Cross-Site Scripting vulnerability could allow admin users to inject malicious code into the plugin settings, which could then execute on other users' devices and compromise their accounts. The best course of action is to update the plugin to the latest version and ensure that all admin privileges are assigned only to trusted users. Stay informed and stay safe!

Timeline

Published on: 11/28/2022 14:15:00 UTC
Last modified on: 11/30/2022 03:50:00 UTC