CVE-2024-20353

CVE-2024-20353 is a high-severity (CVSS 8.6) vulnerability in Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD). CISA added it to the Known Exploited Vulnerabilities catalog on April 24, 2024, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by May 1, 2024. CISA does not currently list it as used in ransomware campaigns. Cisco has 102 vulnerabilities in the KEV catalog, 7 of them linked to ransomware.

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.

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-websrvs-dos-X8gNucD2
• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-websrvs-dos-X8gNucD2
• https://blog.talosintelligence.com/arcanedoor-new-espionage-focused-campaign-found-targeting-perimeter-network-devices/
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-20353