CVE-2022-33183 - A Deep Dive into Brocade Fabric OS CLI Vulnerability and Exploitation Techniques

A recent vulnerability, titled CVE-2022-33183, has been discovered in Brocade Fabric OS CLI before versions Brocade Fabric OS v9.1., 9..1e, 8.2.3c, 8.2.cbn5, and 7.4.2.j, which could allow a remote authenticated attacker to perform a stack buffer overflow attack by exploiting the "firmwaredownload" and "diagshow" commands. In this article, we will examine this vulnerability in detail, diving into the internals of the affected commands, and offer practical mitigations to assist administrators in securing their networks against potential threats.

Brocade Fabric OS 7.4.2.j

This vulnerability was categorized as a "stack buffer overflow," which occurs when a program writes more data to a buffer on the stack than what the buffer was allocated to hold. In this case, the vulnerable commands are the "firmwaredownload" and "diagshow" commands within Brocade Fabric OS CLI. To exploit this vulnerability, an attacker must have access to valid user credentials on the affected device.

Code Snippet

Here's a simplified version of the vulnerable code found in the "firmwaredownload" and "diagshow" functions, which demonstrates the vulnerability:

void vulnerable_function(char *user_input) {
    char buffer[1024]; // fixed-size buffer
    strcpy(buffer, user_input); // copying user input to the buffer without checking its length
}

Exploiting the Vulnerability

A remote authenticated attacker can exploit this vulnerability by first gaining access to valid user credentials on the targeted device. Once authenticated, the attacker can craft a specially designed string as input to the "firmwaredownload" or "diagshow" commands, which will cause a buffer overflow in the affected function. As a result, the attacker can overwrite important stack information, such as function return addresses, leading to arbitrary code execution or crashing the affected device.

For more information about the vulnerability, you can check its official CVE page at

CVE-2022-33183 - NVD

For details on the vendor's disclosure of the vulnerability and recommended actions to be taken, you can visit Brocade's security advisory page at:

Brocade Security Advisory - CVE-2022-33183 (Please note that this is a placeholder link because the actual advisory link was not provided.)

To mitigate this vulnerability, users should consider the following

1. Upgrade Brocade Fabric OS CLI to the latest version as mentioned above (v9.1., 9..1e, 8.2.3c, 8.2.cbn5, 7.4.2.j) to address the vulnerability. Follow the vendor's guidelines for updating your systems.

2. Implement network segmentation, limiting or restricting access to the Brocade Fabric OS CLI devices to a select number of users to minimize the risk of unauthorized access.

3. Implement strong authentication practices and use two-factor authentication (2FA) wherever possible to prevent unauthorized access to your devices.

4. Regularly monitor access logs and user activities and perform routine security audits to ensure the integrity and security of your systems.

Conclusion

In this article, we have examined a vulnerability in Brocade Fabric OS CLI (CVE-2022-33183) and its exploit details. By upgrading to the latest version and taking appropriate mitigation steps, users can protect their systems and networks from this stack buffer overflow vulnerability. As always, stay up-to-date with security news and monitor your systems regularly to ensure the highest level of security for your critical infrastructure.

Timeline

Published on: 10/25/2022 21:15:00 UTC
Last modified on: 08/08/2023 14:21:00 UTC