A NULL Pointer Dereference vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated remote BGP neighbor to cause a denial of service via a VPN-flowspec BGP update if it is readvertised and BMP post-policy RIB-out monitoring is configured.
The product dereferences a pointer that it expects to be valid but is NULL.