Cisco has disclosed that state-sponsored hackers, suspected to be from China, have infiltrated government networks globally by exploiting two zero-day vulnerabilities in its firewall appliances over the last 5 months. The vulnerabilities were found in Cisco's Adaptive Security Appliances and Firepower Threat Defense firewalls. This sophisticated cyber espionage campaign, dubbed 'ArcaneDoor', has been active for the last several months, targeting multiple governments' networks and critical infrastructure. Cisco and cybersecurity agencies are currently investigating the full scope of the breach, which has raised significant concerns about national security.