The Cisco Express Forwarding processing module in Cisco IOS XE allows remote attackers to cause a denial of service (device reload) via crafted MPLS packets that are not properly handled during IP header validation, aka Bug ID CSCuj23992.
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.