CVE-2023-22640 : What You Need to Know

This CVE-2023-22640 informational article delves into the details of a specific cybersecurity vulnerability affecting Fortinet products.

Understanding CVE-2023-22640

In this section, we will explore the nature of CVE-2023-22640, its impact, technical details, affected systems, and mitigation strategies.

What is CVE-2023-22640?

CVE-2023-22640 describes an out-of-bounds write vulnerability found in Fortinet FortiOS versions 7.2.0 through 7.2.3, 7.0.0 through 7.0.10, 6.4.0 through 6.4.11, 6.2.0 through 6.2.13, and all versions of 6.0. Additionally, FortiProxy versions 7.2.0 through 7.2.1, 7.0.0 through 7.0.7, and all versions of 2.0, 1.2, 1.1, and 1.0 are affected. This vulnerability could allow an authenticated attacker to execute unauthorized code or commands via specially crafted requests.

The Impact of CVE-2023-22640

The impact of CVE-2023-22640 is significant, with a CVSS v3.1 base score of 7.1 (High severity). The vulnerability has a high impact on confidentiality, integrity, and availability. It requires low privileges for exploitation and has a high attack complexity.

Technical Details of CVE-2023-22640

Let's explore the technical aspects of CVE-2023-22640, including vulnerability description, affected systems, and exploitation mechanism.

Vulnerability Description

The vulnerability involves an out-of-bounds write in Fortinet FortiOS and FortiProxy versions. It allows an authenticated attacker to execute unauthorized code or commands through specific requests.

Affected Systems and Versions

Fortinet FortiOS versions 7.2.0 to 7.2.3, 7.0.0 to 7.0.10, 6.4.0 to 6.4.11, 6.2.0 to 6.2.13, and all versions of 6.0 are impacted. Similarly, FortiProxy versions 7.2.0 to 7.2.1, 7.0.0 to 7.0.7, and all versions of 2.0, 1.2, 1.1, and 1.0 are affected by this vulnerability.

Exploitation Mechanism

An authenticated attacker can exploit this vulnerability through specially crafted requests, allowing them to execute unauthorized code or commands.

Mitigation and Prevention

To address CVE-2023-22640 and enhance cybersecurity, the following mitigation and prevention measures are recommended:

Immediate Steps to Take

Upgrade to FortiOS version 7.4.0 or above.
Upgrade to FortiOS version 7.2.4 or above.
Upgrade to FortiOS version 7.0.11 or above.
Upgrade to FortiOS version 6.4.12 or above.
Upgrade to FortiOS version 6.2.14 or above.
Upgrade to FortiProxy version 7.2.2 or above.
Upgrade to FortiProxy version 7.0.8 or above.

Long-Term Security Practices

Disable "Host Check", "Restrict to Specific OS Versions", and "MAC address host checking" in the sslvpn portal configuration as a workaround. For example, in the "full-access" sslvpn portal configuration, follow the provided steps.

Patching and Updates

Regularly check for security updates and patches for Fortinet products to mitigate potential vulnerabilities and enhance overall cybersecurity posture.