Chrome Unsafe Port List.Google Chrome has several built-in protection mechanisms to prevent attacks over the Internet. Now, the browser has decided to block access to seven new TCP ports on our local network to prevent these attacks. Therefore, we are going to see which ports are the ones that you will not be able to use, and the reason why they have blocked those seven new ports in particular.
All current routers use a feature called NAT, or Network Address Translation. With a shortage of public IP addresses, each device cannot have its own, so the router creates a local network to “route” Internet access requests from devices through local IP addresses.
Chrome Unsafe Port List.ports that Chrome blocks and you can’t use
NAT Slipstreaming 2.0: the new attack on the web
However, three security researchers named Sammy Kamkar, Ben Seri, and Gregory Vishnipolsky have discovered a new version of the NAT Slipstreaming vulnerability. This vulnerability allows a web page to host malicious scripts that send a message that bypasses the visitor’s NAT firewall to access any TCP / UDP port on the user’s internal network.
When the vulnerability was first published, Google stated that it would block HTTP and HTTPS access to ports 5060 and 5061 to protect against this issue in Chrome 87. However, today Chrome announced that it will block HTTP access , HTTPS and FTP to TCP ports 69, 137, 161, 1719, 1720, 1723, and 6566, avoiding having to close ports in Windows 10 Firewall manually.
This new version of the attack, dubbed NAT Slipstream 2.0, is a kind of inter-protocol request forgery that allows malicious Internet servers to attack computers on a private network. The attack depends mainly on being able to send traffic to port 1720. However, to prevent future attacks, Google has decided to block more ports that they know are frequently inspected by NAT devices and can suffer the same attack.
ERR_UNSAFE_PORT: error that appears on the websites that use them
Thus, when a user tries to connect to a website using these ports, Google Chrome will now show an error saying ” This website cannot be accessed “, with the Chrome error code ERR_UNSAFE_PORT . So if you have a web page that uses those ports to work, you should change them so that users can access it.
Firefox, Edge and Safari 14.0.3 have already implemented solutions to mitigate these security flaws, but we don’t know which ports they will use. In Edge’s case, it will most likely use the same ports as Chrome.
