https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-1000369
https://lists.exim.org/lurker/message/20170621.060753.ee8a6319.en.html
https://github.com/Exim/exim/commit/65e061b76867a9ea7aeeb535341b790b90ae6c21
https://www.qualys.com/2017/06/19/stack-clash/stack-clash.txt