Zyxel, a networking device manufacturer based in Taiwan, is urging customers to update the firmware of certain firewall devices to protect against recently patched vulnerabilities. The vulnerabilities, tracked as CVE-2023-28771, CVE-2023-33009, and CVE-2023-33010, can lead to OS command execution, remote code execution, and denial-of-service attacks. Zyxel released patches for these vulnerabilities after they were discovered in April and May. The company is now warning of ongoing attacks and advising customers to install the available patches promptly. Zyxel also provides additional recommendations for enhancing security and detecting potential malware infections.