A recently discovered vulnerability, designated as CVE-2023-33798, affects the popular open-source data center infrastructure management (DCIM) system, Netbox. Netbox v3.5.1 has a vulnerability that allows an attacker to execute arbitrary web scripts or HTML on the victim's browser via a stored cross-site scripting (XSS) attack. This blog post provides an in-depth analysis of the vulnerability, explains how to exploit it, and shares best practices to prevent such exploits in the future.

Vulnerability Details

The vulnerability lies in the Create Rack (/dcim/rack/) function of Netbox, specifically in the Name field. An attacker can inject a crafted payload into the Name field, which is then rendered as part of the HTML page when the victim views the rack details. As a result, the attacker's payload will be executed in the context of the victim's browser session, potentially giving the attacker access to sensitive data or control over the victim's interactions with the application.

The following code snippet demonstrates a simple payload that exploits the vulnerability

<script>alert('XSS');</script>

By injecting the above payload into the Name field of a new rack, the script will execute when the victim views the rack details, displaying an alert with the message "XSS".

Mitigation Steps

The developers behind Netbox have addressed this vulnerability in version 3.5.2. To mitigate the risk, users should update their Netbox installations as soon as possible. Additionally, users should regularly check the official website and repository for updates and patches.

Preventing Cross-Site Scripting Vulnerabilities

To prevent cross-site scripting vulnerabilities in web applications, developers should adhere to the following best practices:

Implement proper input validation: Sanitize user input by removing or escaping any malicious code.

2. Encode output: Encode dynamic content inserted into the HTML page to prevent potentially dangerous characters from being interpreted as executable code.
3. Limit user-generated content: Restrict user-generated content to certain fields or data types, reducing the likelihood of introducing an XSS vulnerability.

Conclusion

Stored cross-site scripting vulnerabilities, like CVE-2023-33798, pose a significant risk to web applications and their users. By maintaining awareness of such vulnerabilities and following best practices, developers and administrators can prevent attacks, protect sensitive data, and ensure a secure environment for their users.

For further details and assistance, refer to the following resources

1. Netbox GitHub Repository: https://github.com/netbox-community/netbox
2. XSS Prevention Cheat Sheet: https://cheatsheetseries.owasp.org/cheatsheets/Cross_Site_Scripting_Prevention_Cheat_Sheet.html
3. CVE-2023-33798 Description: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-33798

Timeline

Published on: 05/24/2023 20:15:00 UTC
Last modified on: 05/27/2023 03:41:00 UTC