The TCP stack in the Linux kernel 3.x does not properly implement a SYN cookie protection mechanism for the case of a fast network connection, which allows remote attackers to cause a denial of service (CPU consumption) by sending many TCP SYN packets, as demonstrated by an attack against the kernel-3.10.0 package in CentOS Linux 7. NOTE: third parties have been unable to discern any relationship between the GitHub Engineering finding and the Trigemini.c attack code.
https://www.exploit-db.com/exploits/41350/
https://security-tracker.debian.org/tracker/CVE-2017-5972
https://packetstormsecurity.com/files/141083/CentOS7-Kernel-Denial-Of-Service.html
https://githubengineering.com/syn-flood-mitigation-with-synsanity/
https://cxsecurity.com/issue/WLB-2017020112
https://bugzilla.redhat.com/show_bug.cgi?id=1422081
https://access.redhat.com/security/cve/cve-2017-5972