CVE-2020-15936 Explained : Impact and Mitigation

Fortinet FortiOS versions 6.4.3 and below, 6.2.5 and below, 6.0.11 and below, 5.6.13 and below are affected by an improper input validation vulnerability that allows attackers to disclose sensitive information.

Understanding CVE-2020-15936

This CVE involves an improper input validation issue in Fortinet FortiOS, potentially leading to the exposure of sensitive data.

What is CVE-2020-15936?

The vulnerability in Fortinet FortiOS versions allows attackers to reveal confidential information through SNI Client Hello TLS packets.

The Impact of CVE-2020-15936

The vulnerability has a CVSS base score of 2.6, indicating a low severity issue with high privileges required and a changed scope.

Technical Details of CVE-2020-15936

This section delves into the specifics of the vulnerability.

Vulnerability Description

The vulnerability stems from improper input validation in Fortinet FortiOS, enabling attackers to extract sensitive data via SNI Client Hello TLS packets.

Affected Systems and Versions

Fortinet FortiOS 6.4.3 and below
Fortinet FortiOS 6.2.5 and below
Fortinet FortiOS 6.0.11 and below
Fortinet FortiOS 5.6.13 and below

Exploitation Mechanism

The vulnerability can be exploited by sending malicious SNI Client Hello TLS packets to the target system, triggering the disclosure of sensitive information.

Mitigation and Prevention

Protecting systems from CVE-2020-15936 is crucial to maintaining security.

Immediate Steps to Take

Apply patches provided by Fortinet to address the vulnerability.
Monitor network traffic for any suspicious activity that could indicate exploitation.

Long-Term Security Practices

Regularly update and patch Fortinet FortiOS to prevent known vulnerabilities.
Implement network segmentation and access controls to limit the impact of potential attacks.

Patching and Updates

Stay informed about security advisories from Fortinet and promptly apply recommended patches to secure the system.