The Quagga BGP daemon (bgpd) prior to version 1.2.3 does not properly bounds check the data sent with a NOTIFY to a peer, if an attribute length is invalid. Arbitrary data from the bgpd process may be sent over the network to a peer and/or bgpd may crash.
https://www.debian.org/security/2018/dsa-4115
https://usn.ubuntu.com/3573-1/
https://security.gentoo.org/glsa/201804-17
https://gogs.quagga.net/Quagga/quagga/src/master/doc/security/Quagga-2018-0543.txt