Google Chrome now blocks HTTP, HTTPS, and FTP access to TCP port 10080 to prevent port abuse in NAT Slipstreaming 2.0 attacks.
Last year, security researcher Samy Kamkar uncovered a new version of the NAT Slipstreaming vulnerability that allows scripts on malicious websites to bypass visitors' NAT firewalls and gain access to any TCP/UDP port on the visitor's internal network.
Using these vulnerabilities, threat actors can perform a wide range of attacks, including modifying router settings and accessing private network services.
Since this vulnerability only works on specific ports monitored by a router's Application Level Gateway (ALG), browser developers block vulnerable ports that don't receive much traffic.
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Currently, Google Chrome blocks FTP, HTTP, and HTTPS access to ports 69, 137, 161, 554, 1719, 1720, 1723, 5060, 5061, and 6566.
Today, Google said it plans to block TCP port 10080 in Chrome, which Firefox has already blocked since November 2020.
In discussions about whether the port should be blocked, the browser developers decided that the Amanda backup software and VMWare vCenter use the port, but would not be affected by the blocking.
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The most worrying point about blocking port 10080 is that some developers may use it as an alternative to port 80.
To allow developers to continue using this port, Google Chrome developer Adam Rice will add a corporate policy that developers can use to bypass the blocking.
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Once a port is blocked, users see an error message stating "ERR_UNSAFE_PORT" when they try to access the port, as shown below.
If you are currently hosting a website on port 10080, you may want to use a different port to allow Google Chrome to continue to access the website.
Information source: bleepingcomputer.com
