On: Show HN: MathB.in – Mathematics pastebin written i...

[susam]

Thank you for your comment. This is a great point! I had not considered this earlier but after looking at https://github.com/edicl/hunchentoot/blob/master/request.lis... it is clear that this could potentially lead to denial of service.

I have now updated the Nginx configuration to block arbitrary headers coming from the remote client and explicitly pass only a limited set of headers to Hunchentoot. So now I have something like this in the Nginx reverse proxy configuration:

  proxy_pass_request_headers off;
  proxy_set_header Accept $http_accept;
  proxy_set_header Content-Length $http_content_length;
  proxy_set_header Content-Type $http_content_type;
  proxy_set_header If-Modified-Since $http_if_modified_since;
  proxy_set_header Referer $http_referer;
  proxy_set_header User-Agent $http_user_agent;
  proxy_set_header X-Forwarded-For $remote_addr;

I will push this configuration to the GitHub repository too sometime this weekend.

[susam → susam]

Here's an update. The Nginx reverse proxy configuration update to work around the memory leakage issue in Hunchentoot has now been pushed to the GitHub repository of MathB.in too.

Commit: https://github.com/susam/mathb/commit/0dcedc0

Nginx configuration: https://github.com/susam/mathb/blob/main/etc/nginx/https.mat...