'ArcaneDoor' cyberspies, suspected to be state-sponsored and aligned with China's interests, exploited two zero-day vulnerabilities in Cisco's Adaptive Security Appliances to access government networks globally. The campaign, named ArcaneDoor, targeted Cisco's firewalls, allowing hackers to spy on network traffic and maintain access even after device reboots. Cisco has since released patches for these vulnerabilities and advises immediate implementation. This incident highlights a broader trend of targeting network edge devices for espionage.