CVE-2022-3833: Stored Cross-Site Scripting Vulnerability in Fancier Author Box by ThematoSoup WordPress Plugin

The Fancier Author Box by ThematoSoup WordPress plugin is widely used by website owners to enhance and manage author information for their sites. However, the plugin (version 1.4 and earlier) contains a serious security vulnerability - a stored cross-site scripting (XSS) exploit. This vulnerability, identified as CVE-2022-3833, could allow high privilege users (such as administrators) to perform stored XSS attacks even when the unfiltered_html capability is disallowed (e.g., in a multisite setup).

In this post, we will discuss the CVE-2022-3833 vulnerability in detail, including the affected plugin versions, how the exploit works, the risks associated with it, and potential mitigation strategies.

Affected Versions

The CVE-2022-3833 vulnerability affects the Fancier Author Box by ThematoSoup WordPress plugin through version 1.4. Website owners using this plugin in their WordPress setups are at risk of experiencing stored XSS attacks.

Exploit Details

The issue stems from the lack of proper sanitization and escaping of specific settings within the Fancier Author Box plugin. Malicious administrators or other high-privilege users can inject malicious JavaScript payloads into certain fields, which will then be executed whenever the affected page loads. The exploit can be executed even when the unfiltered_html capability is disallowed.

Here's a code snippet that demonstrates the potential malicious payload injection

<script>
   // Malicious JavaScript code here
   alert('Hacked: Your website is vulnerable to XSS attacks');
</script>

By injecting this code snippet into one of the vulnerable settings in the Fancier Author Box plugin, a malicious user could potentially gain unauthorized access to sensitive data, alter the website's appearance and behavior, and distribute the exploit to other users visiting the site.

For more information on the CVE-2022-3833 vulnerability, you can refer to the following links

1. Official CVE entry: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-3833
2. ThematoSoup Fancier Author Box WordPress plugin page: https://wordpress.org/plugins/fancier-author-box/
3. Plugin Vulnerability description: https://wpvulndb.com/vulnerabilities/10471

Risks and Potential Impact

The CVE-2022-3833 vulnerability poses a significant risk to websites that use the affected plugin versions. If not mitigated, the exploit could allow malicious users to:

- Gain unauthorized access to sensitive data, such as login credentials, personal information, and user profiles.
- Manipulate the appearance and behavior of a website, potentially driving away visitors, damaging the site's reputation, and impacting search rankings.
- Distribute the stored XSS attacks to other users visiting the website, further compromising the security of the affected website.

Mitigation Strategies

To protect your website from the CVE-2022-3833 vulnerability, we strongly recommend the following steps:

1. Update the Fancier Author Box by ThematoSoup plugin to the latest version available. The plugin developers should release a patched version addressing the vulnerability. Keep an eye on their official website and WordPress plugin page for updates.
2. Implement proper input validation, sanitization, and escaping techniques in the plugin's settings. Ensure that all settings are thoroughly validated and sanitized before they are stored and displayed on the website.
3. Limit user privileges and restrict access to essential features and settings. By reducing the number of high-privilege users, you minimize the risk of insider threats and unauthorized exploitation of the vulnerability.
4. Regularly monitor and perform security audits on your website. Ensure that all installed plugins and themes are up-to-date and scanned for vulnerabilities.

Conclusion

The CVE-2022-3833 vulnerability in the Fancier Author Box by ThematoSoup WordPress plugin poses a significant risk to website owners using the affected plugin versions. By understanding the exploit details and implementing the suggested mitigation strategies, you can protect your website from potential attacks and maintain a safe and secure online presence.

Timeline

Published on: 11/28/2022 14:15:00 UTC
Last modified on: 11/30/2022 03:49:00 UTC