Connections to HTTP, HTTPS or FTP servers on ports 69, 137, 161, 1719, 1720, 1723 or 6566 will fail. This is a mitigation for the NAT Slipstream 2.0 attack: https://www.armis.com/resources/iot-security-blog/nat-slipstreaming-v2-0-new-attack-variant-can-expose-all-internal-network-devices-to-the-internet/. It helps developers by keeping the web platform safe for users.
The NAT Slipstream 2.0 attack is a kind of cross-protocol request forgery which permits malicious internet servers to attack computers on a private network behind a NAT device. The attack depends on being able to send traffic on port 1720 (H.323). To prevent future attacks, this change also blocks several other ports which are known to be inspected by NAT devices and may be subject to similar exploitation.
Status in Chromium
Consensus & Standardization
Last updated on 2021-01-28