CVE-2022-3608: Exploring the Stored Cross-site Scripting (XSS) Vulnerability in GitHub Repository thorsten/phpmyfaq prior to 3.2.-alpha

CVE-2022-3608 refers to a stored Cross-Site Scripting (XSS) vulnerability discovered in the GitHub repository thorsten/phpmyfaq before its 3.2.-alpha release. This vulnerability allows attackers to inject malicious scripts into webpages that other users may view, potentially leading to unauthorized access to sensitive information or even taking over a user's account. In this long-read post, we will discuss how this vulnerability was discovered, its potential consequences, and how it can be exploited by malicious actors. We will also provide code snippets and links to original references for those interested in further reading or understanding the vulnerability in-depth.

A Brief Overview of XSS

Cross-site Scripting (XSS) is a type of security vulnerability that enables attackers to inject client-side scripts into webpages viewed by others. There are three main types of XSS flaws: stored, reflected, and DOM-based. In stored XSS, the malicious payload is permanently stored on the target server, while in reflected XSS, it is stored only temporarily. DOM-based XSS occurs when an attacker manipulates the Document Object Model (DOM) of an affected page using client-side scripts.

2. The Vulnerability: Stored XSS in thorsten/phpmyfaq
The vulnerability in question, tracked as CVE-2022-3608, affects the popular GitHub repository thorsten/phpmyfaq, a knowledge base and FAQ software based on PHP and MySQL. The stored XSS vulnerability exists due to insufficient input validation and output encoding in the FAQ administration panel, leading to the storage of malicious scripts in the FAQ content.

Exploit Details

To exploit this vulnerability, an attacker with access to the PHPMyFAQ administration panel can create a new FAQ entry and insert a malicious script into the content using standard HTML tags. The exploit may look something like this:

<p>Your regular FAQ content here...</p>
<svg onload="alert('XSS')">Here's an SVG image!</svg>

When the malicious FAQ entry is viewed by another user, the script will be executed in their browser. This could enable the attacker to steal sensitive data, like authentication tokens or cookies, or perform unauthorized actions on the user's behalf.

Potential Consequences

The potential consequences of this vulnerability can be severe, particularly if the attacker is able to target users with administrative privileges in the PHPMyFAQ application. The attacker could gain unauthorized access to confidential information and perform actions on other users' behalf, potentially compromising the integrity and security of your PHPMyFAQ installation.

Mitigation and Patch

The vulnerability was addressed in the PHPMyFAQ 3.2.-alpha release, where both input validation and output encoding functions were improved to prevent the storage of malicious scripts in the FAQ content. It is strongly recommended to update your PHPMyFAQ installation to version 3.2.-alpha or later to protect your application from this vulnerability. Additionally, you can apply Content Security Policy (CSP) headers as an extra layer of protection against XSS attacks.

Original References

For those who would like to delve deeper into this vulnerability, please refer to the following resources:

- CVE Details: https://nvd.nist.gov/vuln/detail/CVE-2022-3608
- GitHub Repository: https://github.com/thorsten/phpmyfaq
- PHPMyFAQ Release Notes: https://www.phpmyfaq.de/2022/02/20/phpmyfaq-3-2--alpha

Conclusion

CVE-2022-3608 highlights the importance of constantly staying informed about new vulnerabilities affecting software regularly used for critical tasks such as storing or accessing sensitive information. In this case, the thorsten/phpmyfaq repository was found to have a stored XSS vulnerability, which could have had severe consequences if left unpatched. By understanding and addressing these vulnerabilities, developers can work together to ensure their applications remain secure against potential attacks.

Timeline

Published on: 10/19/2022 13:15:00 UTC
Last modified on: 10/20/2022 19:35:00 UTC