A vulnerability in the management and VPN web servers for Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to incomplete error checking when parsing an HTTP header. An attacker could exploit this vulnerability by sending a crafted HTTP request to a targeted web server on a device. A successful exploit could allow the attacker to cause a DoS condition when the device reloads.
Use CWE-835, Cisco vendor hub and Adaptive Security Appliance Software product page to widen CVE-2024-20353 into its surrounding weakness, vendor, and product context.
Compare it with CVE-2026-20103, CVE-2026-20101 and CVE-2026-20039 for nearby disclosures in the same product family. Additional editorial context is available in Cybersecurity Weekly Roundup: April 22, 2026 — Critical Zero-Days and Framework Failures.