In recent times, cyber-attacks have been increasing in both complexity and frequency, making them a critical concern for the security of internet users, organizations, and network systems. One of such vulnerabilities that attackers exploit is the Cross-Site Scripting (XSS) vulnerability. In this post, we will discuss the CVE-2023-33799 vulnerability, a stored XSS vulnerability discovered in the Create Contacts function of Netbox v3.5.1, and provide a detailed analysis, including code snippets, links to original references, and exploit details.

Details of the Vulnerability

A stored XSS vulnerability (CVE-2023-33799) has been discovered in the Create Contacts function of Netbox v3.5.1. This vulnerability allows attackers to execute arbitrary web scripts or HTML by injecting a crafted payload into the Name field. By exploiting this vulnerability, an attacker can potentially gain unauthorized access, manipulate or steal sensitive information, deface websites, and carry out other malicious activities.

Technical Analysis

The vulnerability occurs due to insufficient input validation on the Name field in the Create Contacts function of Netbox v3.5.1. The application accepts user input without properly validating or encoding it before rendering it on the web page. This allows an attacker to inject malicious code, typically JavaScript, which gets stored in the application and executed when a victim visits the affected web page.

Code Snippet

Below is an example of a code snippet that demonstrates the vulnerability in the Create Contacts function:

from django.forms import ModelForm
from tenancy.models import Contact

class ContactForm(ModelForm):
    class Meta:
        model = Contact
        fields = ['name', 'phone', 'email', 'address']

    def clean(self):
        cleaned_data = super().clean()
        name = cleaned_data.get('name')

        # Vulnerable code - No proper input validation on the "name" field
        if not name:
            self.add_error('name', 'This field is required.')

The following is an example of a simple JavaScript payload that can be injected into the Name field

<script>alert("XSS Vulnerability!");</script>

By injecting this payload into the Name field and submitting the form, the JavaScript code gets stored in the application and executed when a user visits the web page containing the crafted payload.


The developers of Netbox have released a patch for this vulnerability in version 3.5.2. It is highly recommended to update to the latest version of the software to prevent potential exploitation of this vulnerability:

- Download and install Netbox v3.5.2 (or later) from the official website:
- Apply proper input validation, sanitization, and output encoding techniques when handling user-generated content.


CVE-2023-33799 is a critical stored XSS vulnerability in the Create Contacts function of Netbox v3.5.1, which can potentially lead to various security issues if exploited. It is essential to keep software up-to-date and apply best security practices when handling user input to prevent exposure to such vulnerabilities.


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