CVE-2024-21762 Description

CVE-2024-21762 is an out-of-bounds write vulnerability found in the SSL VPN daemon (sslvpnd) of Fortinet FortiOS. This critical security flaw allows an unauthenticated, remote attacker to execute arbitrary code or commands by sending specially crafted HTTP requests to a device with SSL VPN enabled. The vulnerability has been given a critical severity rating with a Common Vulnerability Scoring System (CVSS) score of 9.6. Fortinet has addressed this vulnerability, and it is recommended for users to update their devices to the secure versions to mitigate the risk.

What is Affected By CVE-2024-21762

Mitigation and Remediation For CVE-2024-21762

To mitigate and remediate CVE-2024-21762, it is strongly recommended to apply the patches provided by Fortinet. Specifically, users of Fortinet FortiOS should upgrade their systems to version 7.2.3, 7.0.9, or later, as these versions contain the necessary fixes to address the vulnerability. By updating to these secure versions, organizations can protect their systems against the exploitation of this critical out-of-bounds write vulnerability in the SSL VPN daemon (sslvpnd).

Additionally, Fortinet advises disabling the SSL VPN service if it is not required, as a preventive measure to reduce the attack surface. However, if the SSL VPN service is necessary for your operations, ensure that your FortiOS version is updated to one of the secure versions mentioned above.

It is also good practice to monitor your systems for any unusual activity and to follow best security practices, including using firewalls, intrusion detection/prevention systems, and conducting regular security assessments to identify and mitigate potential vulnerabilities before they can be exploited.

For the most detailed and specific guidance, always refer to official Fortinet security advisories and documentation.

Impact of Successful Exploitation of CVE-2024-21762

The successful exploitation of CVE-2024-21762 could have severe implications. This critical vulnerability, an out-of-bounds write in the SSL VPN daemon (sslvpnd) of Fortinet FortiOS, allows an unauthenticated, remote attacker to execute arbitrary code or commands on a vulnerable device. The impact of such an exploitation includes:

1. Remote Code Execution (RCE): The attacker could execute arbitrary code with the privileges of the affected service. In the context of the SSL VPN service, this could potentially allow the attacker to gain unauthorized access to the network, manipulate network traffic, or establish a foothold for further attacks.

2. Unauthorized Access: By exploiting this vulnerability, an attacker could bypass authentication mechanisms to gain unauthorized access to the network. This could lead to sensitive information disclosure, data theft, or further compromise of networked systems.

3. System Compromise: Successful exploitation could result in the complete compromise of the affected system. An attacker could use the compromised system to launch additional attacks against other internal resources or use it as part of a botnet for malicious activities.

4. Denial of Service (DoS): Although the primary risk is unauthorized access and code execution, in some cases, exploiting such vulnerabilities could lead to service disruptions, affecting the availability of the SSL VPN service and potentially impacting business operations.

The severity of these impacts underscores the importance of promptly applying available patches or mitigations provided by Fortinet, such as upgrading to FortiOS versions 7.2.3, 7.0.9, or later, which address this vulnerability.