The Flex-VPN load-balancing feature in the ipsec-ikev2 implementation in Cisco IOS before 15.1(1)SY3 does not require authentication, which allows remote attackers to trigger the forwarding of VPN traffic to an attacker-controlled destination, or the discarding of this traffic, by arranging for an arbitrary device to become a cluster member, aka Bug ID CSCub93641.
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Ios | Cisco | * | 15.1(1)sy2 (including) |
| Ios | Cisco | 15.1 (including) | 15.1 (including) |
| Ios | Cisco | 15.1(1)sy (including) | 15.1(1)sy (including) |
| Ios | Cisco | 15.1(1)sy1 (including) | 15.1(1)sy1 (including) |