CVE-2020-3555
MediumCVSS 6.8Exploitation Probability (EPSS)
Elevated risk75th percentile - higher than 75% of all known CVEs
Summary
A vulnerability in the SIP inspection process of Cisco ASA and FTD Software could allow an unauthenticated, remote attacker to cause a crash and reload of an affected device, resulting in a DoS condition. The issue is due to a watchdog timeout and crash during cleanup of threads associated with a SIP connection being deleted. An attacker could exploit this by sending a high rate of crafted SIP traffic.
Risk Assessment
The risk is that a remote attacker could disrupt device operation, leading to network service unavailability.
Recommendation
It is recommended to upgrade ASA/FTD software to a patched version and consider limiting or filtering SIP traffic.
Original NVD description (English source)
A vulnerability in the SIP inspection process of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a crash and reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to a watchdog timeout and crash during the cleanup of threads that are associated with a SIP connection that is being deleted from the connection list. An attacker could exploit this vulnerability by sending a high rate of crafted SIP traffic through an affected device. A successful exploit could allow the attacker to cause a watchdog timeout and crash, resulting in a crash and reload of the affected device.