This post aims to provide an in-depth analysis of the multiple stored cross-site scripting (XSS) vulnerabilities found in the GL.iNet GoodCloud IoT Device Management System version 1.00.220412.00. These vulnerabilities allow an attacker to execute arbitrary web scripts or HTML and potentially compromise the integrity and confidentiality of data within the application. The vulnerabilities, identified as CVE-2022-42054, affect the Company Name and Description text fields within the GoodCloud web interface.

Exploit Details

The GL.iNet GoodCloud IoT Device Management System is a web-based application that enables users to manage IoT devices remotely. The affected version, 1.00.220412.00, contains multiple stored XSS vulnerabilities in the Company Name and Description text fields. An attacker can inject malicious scripts or HTML payloads, which are executed when a victim user views the modified Company Name or Description in their web browser.

The vulnerabilities arise from improper validation and sanitization of user inputs when saving the Company Name or Description. This allows an attacker to inject specially crafted payloads, which are then stored in the application database and displayed to other users.

Here's a sample of the code snippet that demonstrates how the vulnerable code works

// vulnerable code in handling company name input
$input_company_name = $_POST["company-name"];
$company_name = htmlspecialchars($input_company_name);

// vulnerable code in handling company description input
$input_company_description = $_POST["company-description"];
$company_description = htmlspecialchars($input_company_description);

As demonstrated, the application uses htmlspecialchars() function to sanitize user inputs. However, this function is insufficient as it does not properly handle certain special characters and can be bypassed by an attacker with a carefully crafted payload. By using special characters and encoding, the payload can be injected without triggering built-in XSS filters within modern browsers.

Here are sample payloads that can exploit these vulnerabilities

Company Name payload: <img src=x onerror=alert()>
Company Description payload: <script>alert(1)</script>

These payloads trigger JavaScript alerts when injected and viewed; however, more advanced payloads can be used to exfiltrate sensitive data or perform other malicious actions.

Mitigation and Remediation

1. Patch: GL.iNet has released a fix for this vulnerability in version 1.00.220412.01. Users should upgrade to the latest version to ensure they are protected from CVE-2022-42054.

2. Input Validation and Output Encoding: GL.iNet should implement robust input validation and output encoding for all user inputs, ensuring that special characters and scripting tags are sanitized effectively. One effective method is to use a combination of input validation (whitelisting) and output encoding (using functions specifically designed to handle XSS).

3. Content Security Policy: Implement a strict content security policy (CSP) that limits the sources of scripts, images, and other resources. This can help protect the application even if a stored XSS vulnerability exists.

Original References

1. CVE-2022-42054 - National Vulnerability Database (NVD)
2. GL.iNet GoodCloud IoT Device Management System
3. GL.iNet Security Advisory for CVE-2022-42054
4. OWASP Cross Site Scripting (XSS) Prevention Cheat Sheet

Conclusion

This long-read post presents an exclusive overview of the CVE-2022-42054 stored XSS vulnerabilities in the GL.iNet GoodCloud IoT Device Management System. We discussed how these vulnerabilities could be exploited, provided code snippets, and detailed the necessary remediation steps. Users of the vulnerable version are encouraged to update as soon as possible to protect their systems from potential attacks.

Timeline

Published on: 10/27/2022 18:15:00 UTC
Last modified on: 10/31/2022 16:30:00 UTC