The issue is related to multiple vulnerabilities in the Quagga package, which can lead to disruption of confidentiality, integrity, and availability of protected information. Exploitation of these vulnerabilities can be done remotely. A heap-based buffer overflow in the `ecommunity ecom2str` function in `bgp ecommunity.c` in `bgpd` in Quagga before version 0.99.19 allows remote attackers to cause a denial of service (daemon crash) or possibly execute arbitrary code by sending a crafted BGP UPDATE message over IPv4.