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I'd like an archived thread made active again (28507-open-ports-on-router-esp-port-7547)


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I'd like to reopen an archived thread. When typing 'ZyXel 7547' into Google, this archived thread is the first result.



The problem was never solved. This port comes by default as open to the WAN on many ZyXel commercial routers, and is easily made explotable. The solution to the problem is as follows:

1. Login to your device via telnet (or ssh if provided).

2. Issue the following command: sys cwmp clearall.

This will stop the port listening on the WAN.

That is all.

- aias

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Thank you very much for opening the thread once more. It turns out that the CWMP port has been heavily exploited. The exploit allows an attacker to change the DNS server settings in the consumer's router, and therefore route a large portion of their web requests to wherever they please (assuming they specifiy their own rogue DNS server's IP, of course). I have updated the thread with a method to disable the service. And it does indeed survive both soft and hard reboots.

- aias

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