In recent news, ZYXEL, a Taiwanese multinational company that manufactures networking products, has been discovered with a Buffer Overflow vulnerability on their ZYXEL-PMG2005-T20B device. This vulnerability can lead to a denial-of-service condition due to improper sanitization of user-supplied input on their HTTP request.
A threat actor can exploit this vulnerability by providing a crafted script to the uid parameter in the cgi-bin/login.asp, which causes a Buffer Overflow and eventually results in a denial-of-service condition. The vulnerability has been assigned the CVE identifier CVE-2023-43314, and its severity is currently being analyzed.
To trigger this vulnerability in the ZYXEL-PMG2005-T20B product, the number of admin in the uid parameter must exceed the maximum threshold of 50. When parsed in the backend, this causes the application to crash. Additionally, the COOKIE header in the HTTP request must be supplied with a SESSIONID parameter to create a valid session with the ZYXEL product.
Further analysis revealed that the ZYXEL-PMG2005-T20B product has reached End-of-Life as per the ZyXEL website. This means that the product is no longer being supported or receiving updates from the manufacturer. This raises concerns about the security posture of devices still in use.
In a demonstration of the vulnerability, a researcher created an HTTP request with specific parameters and values to replicate the vulnerability. This request causes a Buffer Overflow and triggers a denial-of-service condition. The researcher also identified more than 20 URLs affected by the same vulnerability.
To provide more information about this vulnerability, a GitHub repository and a proof-of-concept were published. These resources offer detailed information on the vulnerability’s existence and its implications.
Users of the ZyXEL-PMG2005-T20B device are strongly advised to upgrade to the latest version of the product to prevent exploitation of this vulnerability. By installing the latest version, users can ensure that their devices are protected against this specific vulnerability and potentially other undisclosed vulnerabilities.
Taking proactive steps to protect against vulnerabilities is crucial. One option for users is to utilize Patch Manager Plus, a tool that helps quickly patch over 850 third-party applications. By using such a tool, organizations can ensure that their systems are up-to-date with the latest security patches, reducing the risk of exploitation.
In conclusion, ZYXEL’s ZYXEL-PMG2005-T20B device has been found to have a Buffer Overflow vulnerability, which can result in a denial-of-service condition. Users are advised to upgrade their devices to the latest version and consider implementing tools like Patch Manager Plus to stay protected against vulnerabilities.