CVE-2023-38998 : Security Advisory and Response

An open redirect vulnerability in OPNsense Community Edition before 23.7 and Business Edition before 23.4.2 could allow attackers to redirect users to malicious websites.

Understanding CVE-2023-38998

This article dives into the details of CVE-2023-38998, highlighting the impact, technical aspects, and mitigation strategies.

What is CVE-2023-38998?

CVE-2023-38998 refers to an open redirect flaw in the Login page of OPNsense CE and BE versions before specific releases. It enables attackers to manipulate URLs and lead users to malicious websites.

The Impact of CVE-2023-38998

Exploiting this vulnerability can result in phishing attacks, where users are tricked into accessing fake websites designed to steal sensitive information such as login credentials or payment details.

Technical Details of CVE-2023-38998

The following section provides insights into the vulnerability description, affected systems, and the exploitation mechanism.

Vulnerability Description

The vulnerability allows attackers to craft URLs that redirect users visiting the OPNsense login page to arbitrary websites under the attacker's control.

Affected Systems and Versions

Both OPNsense Community Edition and Business Edition before versions 23.7 and 23.4.2, respectively, are impacted by this vulnerability.

Exploitation Mechanism

By sending specially crafted URLs to victims, attackers can manipulate the redirection behavior of the Login page, potentially leading users to malicious websites.

Mitigation and Prevention

Protecting systems and users from CVE-2023-38998 involves taking immediate steps and implementing long-term security practices.

Immediate Steps to Take

Update OPNsense CE and BE to versions 23.7 and 23.4.2, respectively, to patch the vulnerability.
Avoid clicking on suspicious or unverified links that appear in emails or messages.

Long-Term Security Practices

Educate users about the risks of phishing attacks and how to identify suspicious URLs.
Regularly monitor and audit website redirection mechanisms to detect and prevent such vulnerabilities.

Patching and Updates

Stay informed about security updates and patches provided by OPNsense, ensuring timely application to secure systems against known vulnerabilities.