CVE-2021-40125
MediumCVSS 5.3Exploitation Probability (EPSS)
Elevated risk59th percentile - higher than 59% of all known CVEs
Summary
A vulnerability in the IKEv2 implementation of Cisco ASA and FTD Software could allow an authenticated, remote attacker to trigger a denial of service (DoS) condition. This is due to improper resource control. An attacker who can spoof a trusted IKEv2 site-to-site VPN peer and has valid credentials could send malformed, authenticated IKEv2 messages, causing a device reload.
Risk Assessment
The risk is the potential for an attacker to disrupt device operation, leading to network service unavailability and organizational downtime.
Recommendation
It is recommended to update the software to a patched version, restrict trusted IKEv2 sources, and monitor logs for unusual activity.
Original NVD description (English source)
A vulnerability in the Internet Key Exchange Version 2 (IKEv2) implementation of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to trigger a denial of service (DoS) condition on an affected device. This vulnerability is due to improper control of a resource. An attacker with the ability to spoof a trusted IKEv2 site-to-site VPN peer and in possession of valid IKEv2 credentials for that peer could exploit this vulnerability by sending malformed, authenticated IKEv2 messages to an affected device. A successful exploit could allow the attacker to trigger a reload of the device.