CVE-2023-36639 : Exploit Details and Defense Strategies

A use of externally-controlled format string vulnerability has been identified in multiple Fortinet products, allowing attackers to execute unauthorized code or commands via specially crafted API requests.

Understanding CVE-2023-36639

This section provides insights into the vulnerability, its impact, technical details, and mitigation strategies.

What is CVE-2023-36639?

The CVE-2023-36639 vulnerability involves a use of externally-controlled format string in Fortinet FortiProxy and FortiOS products. Attackers exploiting this flaw can execute unauthorized code or commands by sending specially crafted API requests.

The Impact of CVE-2023-36639

The impact of this vulnerability is classified as high, with a CVSS base score of 7. It can result in a compromise of confidentiality, integrity, and availability of the affected systems.

Technical Details of CVE-2023-36639

This section delves into the specific technical aspects of the CVE-2023-36639 vulnerability.

Vulnerability Description

The vulnerability exists in Fortinet FortiProxy versions 7.2.0 through 7.2.4, 7.0.0 through 7.0.10, FortiOS versions 7.4.0, 7.2.0 through 7.2.4, 7.0.0 through 7.0.11, 6.4.0 through 6.4.12, 6.2.0 through 6.2.15, and 6.0.0 through 6.0.17, as well as FortiPAM versions 1.0.0 through 1.0.3.

Affected Systems and Versions

The vulnerability impacts multiple versions of Fortinet products, including FortiProxy, FortiOS, and FortiPAM, as detailed in the vulnerability descriptions.

Exploitation Mechanism

Attackers exploit this vulnerability by leveraging externally-controlled format strings in API requests to execute unauthorized code or commands on vulnerable systems.

Mitigation and Prevention

Protecting systems from CVE-2023-36639 requires immediate action and long-term security practices.

Immediate Steps to Take

Upgrade to FortiOS version 7.4.1 or above
Upgrade to FortiOS version 7.2.5 or above
Upgrade to FortiOS version 7.0.12 or above
Upgrade to FortiOS version 6.4.13 or above
Upgrade to FortiOS version 6.2.16 or above
Upgrade to FortiPAM version 1.2.0 or above
Upgrade to FortiPAM version 1.1.1 or above
Upgrade to FortiProxy version 7.4.0 or above
Upgrade to FortiProxy version 7.2.5 or above
Upgrade to FortiProxy version 7.0.11 or above
Upgrade to FortiSASE version 23.3 or above

Long-Term Security Practices

In addition to immediate updates, maintaining secure coding practices and regularly updating systems can help prevent such vulnerabilities in the future.

Patching and Updates

Regularly check for security advisories and apply patches provided by Fortinet to address vulnerabilities and enhance the security posture of your systems.