CVE-2021-36173 : Security Advisory and Response

A heap-based buffer overflow vulnerability has been identified in the firmware signature verification function of several Fortinet FortiOS versions. This vulnerability may allow an attacker to execute arbitrary code by using specially crafted installation images.

Understanding CVE-2021-36173

This section will delve into the details of the CVE-2021-36173 vulnerability, including its impact and technical aspects.

What is CVE-2021-36173?

The heap-based buffer overflow in FortiOS versions 7.0.1, 7.0.0, 6.4.0 through 6.4.6, 6.2.0 through 6.2.9, and 6.0.0 through 6.0.13 enables attackers to potentially execute malicious code through manipulated installation images.

The Impact of CVE-2021-36173

The low complexity of attack vectors and high impact on confidentiality, integrity, and availability make CVE-2021-36173 a significant threat. The vulnerability receives a base score of 7.3, indicating a high severity level.

Technical Details of CVE-2021-36173

This section will provide technical insights into the CVE-2021-36173 vulnerability, including its description, affected systems, and exploitation mechanism.

Vulnerability Description

The vulnerability arises from a heap-based buffer overflow in the firmware signature verification function of FortiOS, allowing threat actors to exploit the system via specially crafted installation images.

Affected Systems and Versions

Fortinet FortiOS versions 7.0.1, 7.0.0, 6.4.0 through 6.4.6, 6.2.0 through 6.2.9, and 6.0.0 through 6.0.13 are susceptible to this heap-based buffer overflow vulnerability.

Exploitation Mechanism

Attackers can exploit CVE-2021-36173 by providing malicious installation images that trigger the buffer overflow, leading to arbitrary code execution.

Mitigation and Prevention

In this section, we will discuss immediate steps to take and long-term security practices to mitigate the risks associated with CVE-2021-36173.

Immediate Steps to Take

It is crucial to apply workarounds and security best practices to safeguard systems against potential attacks leveraging CVE-2021-36173. Network administrators should closely monitor for any suspicious activities.

Long-Term Security Practices

Implementing a robust security policy, conducting regular security audits, and keeping systems up to date with the latest patches are essential practices to prevent exploitation of vulnerabilities like CVE-2021-36173.

Patching and Updates

Fortinet has released patches to address the vulnerability in FortiOS versions. Ensure timely installation of these patches to mitigate the risk of exploitation.