A vulnerability in the Layer 2 Ethernet services of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to cause the line card network processor to reset, resulting in a denial of service (DoS) condition. This vulnerability is due to the incorrect handling of specific Ethernet frames that are received on line cards that have the Layer 2 services feature enabled. An attacker could exploit this vulnerability by sending specific Ethernet frames through an affected device. A successful exploit could allow the attacker to cause the ingress interface network processor to reset, resulting in a loss of traffic over the interfaces that are supported by the network processor. Multiple resets of the network processor would cause the line card to reset, resulting in a DoS condition.