5 ms·

Maybe it's a remote administration port for your ISP. I have a router provided by Froniter, formerly Verizon FiOS, where port 4567 is always open and cannot be

Maybe it's a remote administration port for your ISP. I have a router provided by Froniter, formerly Verizon FiOS, where port 4567 is always open and cannot be closed with a firewall rule from the router's web UI (grayed out). After some googling I found out that it's their maintenance port: https://www.speedguide.net/port.php?port=4567 https://www.speedguide.net/port.php?port=4567 For a while I had my own OpenWRT router in place of the ISP one, but I think they got wise to it and blocked the MAC. I changed it to match the ISP router's MAC address, but it only worked for about 3 minutes before being blocked again.

AdmiralAsshat 7y ago
I bought both my modem and my router, so I'd be a little incredulous if my ISP had somehow forced a port open on it. The 20005 one may be some port that NetGear uses for its USB Printing, I've found some articles that mention it. It also struck me that I hit it with nmap using the LAN IP, so perhaps these are only open within the network. I probably need to hit the external IP of the router to see what is externally open. ShieldsUP! didn't show anything unusual.[1] EDIT: Disclosure of a vulnerability regarding port 20005[2], and Netgear confirming that it does affect my router[3], but should have been fixed. I assume the "fix" was fixing the buffer overflow vulnerability, rather than closing the port altogether. [1] https://www.grc.com/x/ne.dll?bh0bkyd2 https://www.grc.com/x/ne.dll?bh0bkyd2 [2] https://www.kb.cert.org/vuls/id/177092/ https://www.kb.cert.org/vuls/id/177092/ [3] https://kb.netgear.com/28393/NETGEAR-Product-Vulnerability-Advisory-ReadySHARE https://kb.netgear.com/28393/NETGEAR-Product-Vulnerability-A...