Pierluigi Paganini February 27, 2024

Taiwanese vendor Zyxel warns of security vulnerabilities in its firewalls and access points, including a remote code execution flaw.

Taiwanese networking vendor Zyxel addressed four vulnerabilities, respectively tracked as CVE-2023-6397, CVE-2023-6398, CVE-2023-6399, and CVE-2023-6764, in its firewalls and access points.

The flaws can be exploited by threat actors to carry out command injection and denial-of-service attacks and to achieve remote code execution.

Below is the list of the flaws addressed by the company:

• CVE-2023-6397 – A null pointer dereference vulnerability in some firewall versions could allow a LAN-based attacker to cause denial-of-service (DoS) conditions by downloading a crafted RAR compressed file onto a LAN-side host if the firewall has the “Anti-Malware” feature enabled.
• CVE-2023-6398 – A post-authentication command injection vulnerability in the file upload binary in some firewall and AP versions could allow an authenticated attacker with administrator privileges to execute some operating system (OS) commands on an affected device via FTP.
• CVE-2023-6399 – A format string vulnerability in some firewall versions could allow an authenticated IPSec VPN user to cause DoS conditions against the “deviceid” daemon by sending a crafted hostname to an affected device if it has the “Device Insight” feature enabled.
• CVE-2023-6764 – A format string vulnerability in a function of the IPSec VPN feature in some firewall versions could allow an attacker to achieve unauthorized remote code execution by sending a sequence of specially crafted payloads containing an invalid pointer; however, such an attack would require detailed knowledge of an affected device’s memory layout and configuration.

Below are the lists of impacted devices:

Table 2. APs affected by CVE-2023-6398

The Taiwanese vendor acknowledged Lays and atdog from TRAPA Security for reporting these flaws.

Customers are recommended to install the security patches as soon as possible.

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Pierluigi Paganini

(SecurityAffairs – hacking, cyberattack)