Actively exploited in the wild
Cisco ASA and FTD Denial of Service Vulnerability
Cisco - Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) · Listed in the CISA KEV since 2024-04-24. This indicates confirmed attacks in production environments.
Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
CVE-2024-20353
HighCVSS 8.6KEVExploitation Probability (EPSS)
Very high risk99th percentile - higher than 99% of all known CVEs
Summary
A vulnerability in the management and VPN web servers of Cisco ASA and FTD Software allows an unauthenticated, remote attacker to cause an unexpected reload, resulting in DoS. The issue is due to incomplete error checking when parsing an HTTP header. A successful exploit could cause a DoS condition when the device reloads.
Risk Assessment
Risk of device downtime (DoS), impacting availability of network and VPN services.
Recommendation
Apply Cisco updates and restrict access to management and VPN servers to trusted sources only.
Original NVD description (English source)
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.