CVE-2019-3961 Explained : Impact and Mitigation

A security issue has been identified in Nessus versions 8.4.0 and prior, involving a reflected XSS vulnerability due to insufficient validation of user input.

Understanding CVE-2019-3961

This CVE entry highlights a Cross-Site Scripting vulnerability in Tenable Nessus versions.

What is CVE-2019-3961?

The vulnerability in Nessus versions 8.4.0 and earlier allows an unauthenticated outsider to inject and execute malicious script code in a user's browser session through a crafted request.

The Impact of CVE-2019-3961

If successfully exploited, an attacker could execute arbitrary script code within a user's browser session without authentication, potentially leading to unauthorized actions.

Technical Details of CVE-2019-3961

This section provides detailed technical insights into the vulnerability.

Vulnerability Description

The vulnerability arises from improper validation of user-supplied input in Tenable Nessus versions 8.4.0 and earlier, enabling a reflected XSS attack.

Affected Systems and Versions

Product: Tenable Nessus
Vendor: Tenable
Versions Affected: All versions prior to 8.5.0

Exploitation Mechanism

The vulnerability can be exploited by an attacker sending a specially crafted request to the target system, allowing the execution of malicious script code in the user's browser session.

Mitigation and Prevention

Protecting systems from CVE-2019-3961 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update Tenable Nessus to version 8.5.0 or later to mitigate the vulnerability.
Monitor network traffic for any suspicious activities that could indicate an exploitation attempt.

Long-Term Security Practices

Implement input validation mechanisms to prevent XSS attacks.
Educate users on safe browsing practices to minimize the risk of executing malicious scripts.

Patching and Updates

Regularly apply security patches and updates provided by Tenable to address known vulnerabilities and enhance system security.