Microweber 2.0.15 Stored XSS Vulnerability Exposed

Introduction

The Microweber platform, widely used for building websites and managing content, has recently been found to contain a critical vulnerability: a Stored Cross-Site Scripting (XSS) flaw in version 2.0.15. This vulnerability allows attackers to inject malicious scripts into web pages viewed by other users, potentially compromising their data and privacy.

Understanding Stored XSS

Stored XSS occurs when an attacker manages to store malicious scripts on a target server. When users access the compromised data, the server sends the malicious payload back to their browsers. This means that the attack can affect users even without them clicking on a suspicious link.

Entry Point of the Vulnerability

In Microweber 2.0.15, the vulnerability exists primarily in the way it handles user-generated content. Attackers can exploit this by submitting a payload through specific parameters that are not adequately sanitized. The affected endpoint allows users to submit content without proper validation, making it an ideal target for such attacks.

Attack Parameters

The vulnerable parameters can be demonstrated using HTTP POST requests. Malicious users can send harmful inputs to the following endpoints:

• /api/v2/pages – where users can create or edit pages.
• /api/v2/comments – where users can leave comments on posts.

Both of these endpoints accept parameters that can be manipulated. It’s crucial to note that this vulnerability is non-authenticated, allowing anyone to exploit it without needing user credentials.

Payload Exploitation

For this specific attack, the payload may include JavaScript that executes when the compromised page is loaded. An illustrative payload could look something like this:

<script>alert(‘XSS Vulnerability Exploited!’)</script>

When a user visits a page containing this payload, the malicious script is executed in their browser, which could lead to session hijacking or data theft. Attackers could also use encoded payloads to bypass simple filters:

<img src=x onerror=alert(‘Hacked!’)>

Technical Details of the Attack

The attack process can be visualized as follows:

1. User submits a payload to the target endpoint (e.g., /api/v2/pages).
2. The Microweber application stores the payload in its database.
3. Another user accesses the stored page or comment.
4. The application fetches the stored payload and renders it as part of the HTML response.
5. The user’s browser executes the malicious script.

Mitigating the Vulnerability

To effectively mitigate the risks associated with the Stored XSS vulnerability in Microweber 2.0.15, it is crucial to implement strict input validation and output encoding.

• Input validation: Ensure that all user inputs are strictly validated for type and length before storage. Reject any input that includes suspicious or unexpected characters.
• Output encoding: Encode data before rendering it in web pages to neutralize any scripts. This can include converting characters such as <, >, and & into their respective HTML entities.

Related Attack Vectors

Beyond the primary endpoint mentioned, other vectors may also be compromised due to the lack of proper sanitization. By manipulating parameters in various API calls, attackers can exploit weaknesses in file uploads, comments, or user profiles. These vectors demonstrate the critical importance of comprehensive security measures across all input channels.

Conclusion

The discovery of a Stored XSS vulnerability in Microweber 2.0.15 serves as a reminder of the potential risks associated with web applications that do not adequately handle user inputs. Security measures are vital to protect users from various attack vectors. By implementing strict input validation and output encoding as immediate mitigation steps, the integrity and security of web applications can be substantially improved.

If you’re looking to strengthen your overall cybersecurity posture, consider exploring SecureLayer7’s offensive security and API security solutions. We help organizations identify and mitigate vulnerabilities, ensuring your data remains safe.

References

Credit to the original discoverer and source of vulnerability information: Exploit-DB.