Invalid response from web ui breaks reverse proxy.
The web server on this gateway produces a response to initial connection that violates RFC 9112 and breaks rfc compliant reverse proxies, such as NGINX.
# curl http://192.168.3.1 -v
* Trying 192.168.3.1:80...
* Connected to 192.168.3.1 (192.168.3.1) port 80 (#0)
> GET / HTTP/1.1
> Host: 192.168.3.1
> User-Agent: curl/7.88.1
> Accept: */*
>
< HTTP/1.1 200 OK
< Connection: close
< Transfer-Encoding: chunked
< ETag: "15aa-110-68e78c75"
< Last-Modified: Thu, 09 Oct 2025 10:20:37 GMT
< Date: Thu, 13 Nov 2025 03:48:15 GMT
< X-Frame-Options: sameorigin
< Content-Security-Policy: frame-ancestors 'self'
< Content-Type: text/html
< Content-Length: 272 ### Content-Length header should not be sent in same request with Transfer-Encoding header!!
### RFC 9112 states that "a sender (server) MUST NOT send a Content-Length header field in any message that contains a Transfer-Encoding header field."
<
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="refresh" content="0; URL=/webpages/login.html" />
</head>
</html>
This issue also exists with the ER605 if my research is correct. I see history of this issue going back years, but haven't found any discussion here, although the "Start a new Thread" button seems to be taking me on an endless loop of trying to redirect me to the US forums, so who knows if the search is working.
Could you request the firmware team drop the non-conforming "Content-Length" response?
Thanks.
