A vulnerability in the Internet Key Exchange (IKE) module of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to delete established security associations on an affected device.
The vulnerability is due to improper handling of rogue IKE Main Mode packets. An attacker could exploit this vulnerability by sending a crafted IKE Main Mode packet to an affected device. An exploit could allow the attacker to cause valid, established IKE security associations on an affected device to drop.
Cisco has confirmed the vulnerability in a security notice and released software updates.
To exploit this vulnerability, an attacker may need access to trusted, internal networks to send crafted IKE Main Mode packets to a targeted device. This access requirement may reduce the possibility of a successful exploit.
Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.