The Quagga BGP daemon (bgpd) prior to version 1.2.3 has a bug in its parsing of Capabilities in BGP OPEN messages, in the bgp_packet.c:bgp_capability_msg_parse function. The parser can enter an infinite loop on invalid capabilities if a Multi-Protocol capability does not have a recognized AFI/SAFI, causing a denial of service. https://nvd.nist.gov/vuln/detail/CVE-2018-5381
