A zero day that allows nearby network actors to detect and inject payloads into VPN tunnels has been revealed (archived). All VPN implementations appear to be affected including allegedly "hardened" ones like WireGuard and IKEv2/IPSec while the vulnerability hits numerous *nix TCP/IP stacks including those by Apple, Google, OpenBSD, and Linux. Linux appear to be most gravely affected when running versions of systemd published after November 28th, 2018 when the default "reverse ip path filtering" default was changed to more easily facilitate hijacking VPN sessions in this manner.
The original disclosures to the Openwall oss-security mailing lists are presented in full below: Continue reading