A vulnerability in the IPsec component of StarOS for Cisco ASR 5000 Series routers could allow an unauthenticated, remote attacker to terminate all active IPsec VPN tunnels and prevent new tunnels from establishing, resulting in a denial of service (DoS) condition. This vulnerability affects the following Cisco products: Cisco ASR 5000/5500 Series routers, Cisco Virtualized Packet Core (VPC). More Information: CSCva13631. Known Affected Releases: 20.0.0 20.1.0 20.2.0 20.2.3 20.2.v1 21.0.0 21.0.M0.64246. Known Fixed Releases: 20.2.3 20.2.3.65026 20.2.a4.65307 20.2.v1 20.2.v1.65353 20.3.M0.65037 20.3.T0.65043 21.0.0 21.0.0.65256 21.0.M0.64595 21.0.M0.64860 21.0.M0.65140 21.0.V0.65052 21.0.V0.65150 21.0.V0.65366 21.0.VC0.64639 21.1.A0.64861 21.1.A0.65145 21.1.PP0.65270 21.1.R0.65130 21.1.R0.65135 21.1.R0.65154 21.1.VC0.64898 21.1.VC0.65203 21.2.A0.65147.