
CVE-2024-20353 ArcaneDoor Explained: Cisco ASA Zero-Days
CVE-2024-20353 and CVE-2024-20359 are two Cisco ASA and FTD zero-day vulnerabilities exploited in the ArcaneDoor espionage campaign by a suspected Chinese state-sponsored actor. The flaws enabled persistent backdoor implants (Line Dancer and Line Runner) on perimeter VPN devices protecting government and critical infrastructure networks across multiple countries. First exploitation observed in November 2023, five months before public disclosure.


