CVE-2017-6770: Input Validation

Cisco IOS 12.0 through 15.6, Adaptive Security Appliance (ASA) Software 7.0.1 through 9.7.1.2, NX-OS 4.0 through 12.0, and IOS XE 3.6 through 3.18 are affected by a vulnerability involving the Open Shortest Path First (OSPF) Routing Protocol Link State Advertisement (LSA) database. This vulnerability could allow an unauthenticated, remote attacker to take full control of the OSPF Autonomous System (AS) domain routing table, allowing the attacker to intercept or black-hole traffic. The attacker could exploit this vulnerability by injecting crafted OSPF packets. Successful exploitation could cause the targeted router to flush its routing table and propagate the crafted OSPF LSA type 1 update throughout the OSPF AS domain. To exploit this vulnerability, an attacker must accurately determine certain parameters within the LSA database on the target router. This vulnerability can only be triggered by sending crafted unicast or multicast OSPF LSA type 1 packets. No other LSA type packets can trigger this vulnerability. OSPFv3 is not affected by this vulnerability. Fabric Shortest Path First (FSPF) protocol is not affected by this vulnerability. Cisco Bug IDs: CSCva74756, CSCve47393, CSCve47401.