CVE-2023-3479: Reflected XSS in HestiaCP

Introduction

During my security research activities, I discovered a reflected Cross-Site Scripting (XSS) vulnerability in HestiaCP, a popular web hosting control panel. This vulnerability was assigned CVE-2023-3479 and has been officially documented in the National Vulnerability Database.

Vulnerability Details

CVE ID: CVE-2023-3479
CVSS Score: 6.1 (Medium)
Vulnerability Type: Reflected Cross-Site Scripting (XSS)
Affected Software: HestiaCP

Discovery Process

The vulnerability was discovered during a routine security assessment of the HestiaCP interface. I noticed that certain user input parameters were not properly sanitized before being reflected back in the HTTP response.

Technical Analysis

The vulnerability exists in the web interface where user-supplied input is reflected back to the user without proper encoding or validation. This allows an attacker to inject malicious JavaScript code that gets executed in the victim's browser context.

Vulnerable Parameter: The vulnerability was found in a specific parameter that handles user input for administrative functions.

Attack Vector: An attacker could craft a malicious URL containing JavaScript payload and trick an administrator into clicking it.

Proof of Concept

```javascript // Example payload (sanitized for educational purposes)

<script>alert('XSS Vulnerability Detected')</script>

```

When this payload is properly crafted and embedded in the vulnerable parameter, it executes in the context of the HestiaCP administrative interface.

Impact Assessment

This vulnerability could allow an attacker to:

• Steal session cookies and authentication tokens
• Perform administrative actions on behalf of the victim
• Redirect users to malicious websites
• Inject malicious content into the administrative interface

Remediation

The vulnerability has been addressed by the HestiaCP development team through:

1. Input Validation: Implementing proper input validation for all user-supplied parameters
2. Output Encoding: Ensuring all user input is properly encoded before being reflected in responses
3. Content Security Policy: Implementing CSP headers to mitigate XSS attacks

Timeline

• Discovery Date: March 2023
• Vendor Notification: March 2023
• CVE Assignment: June 2023
• Public Disclosure: July 2023

Lessons Learned

This discovery reinforces the importance of:

• Regular security assessments of web applications
• Proper input validation and output encoding
• Following secure coding practices
• Implementing defense-in-depth security measures

References

• CVE-2023-3479 - NVD
• HestiaCP Security Advisory
• OWASP XSS Prevention Cheat Sheet

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This blog post is for educational purposes and demonstrates the importance of responsible vulnerability disclosure.