Description

According to reports, three critical-severity remote code execution vulnerabilities have been discovered in ASUS routers, notably the RT-AX55, RT-AX56U_V2, and RT-AC86U models. These routers are popular among customers, particularly gamers and users with high performance demands. Failure to deploy security updates may expose these devices to a possible takeover by hostile actors. All three vulnerabilities have a high CVSS v3.1 score of 9.8 out of 10, fall under the category of format string vulnerabilities, and enable remote exploitation without authentication. The three vulnerabilities disclosed are as follows: CVE-2023-39238: Lack of proper input format string verification in the iperf-related API module 'ser_iperf3_svr.cgi'. CVE-2023-39239: Lack of proper input format string verification in the general setting function's API CVE-2023-39240: Lack of proper input format string verification in the iperf-related API module 'ser_iperf3_cli.cgi'. The successful exploitation by attackers enables them to remotely execute code, stop services, and do arbitrary tasks on the infected device. Unvalidated or improperly sanitized user input inside the format string arguments of some methods causes format string vulnerabilities, which can result in a number of security risks, including data exposure and code execution. Furthermore, to exploit these vulnerabilities, attackers use carefully crafted input sent to the vulnerable devices, specifically targeting certain administrative API functions on ASUS routers. Moreover, these vulnerabilities affect ASUS RT-AX55, RT-AX56U_V2, and RT-AC86U routers running firmware versions 3.0.0.4.386_50460, 3.0.0.4.386_50460, and 3.0.0.4_386_51529, respectively. ASUS has released patches to address these vulnerabilities in early August 2023 for the RT-AX55, in May 2023 for the AX56U_V2, and in July 2023 for the RT-AC86U. It is crucial for users to promptly apply these updates to safeguard their devices from potential exploitation.