GitBook bypassing Cloudflare DNS to route traffic to their domain

Re:GitBook bypassing Cloudflare DNS to route traffic to thei... by jivings on Wednesday November 23, 2022 @12:31AM (#33715599)

You can see this yourself by running a "dig" against help.leavemealone.app, the DNS resolution and where the domain actually routes to is different.

[ Parent | on HN ]

Re:GitBook bypassing Cloudflare DNS to route traffic to thei... by aussiedude on Wednesday November 23, 2022 @01:28AM (#33715903)

I was honestly confused for a bit, then realised that your site was redirecting to Gitbook.

;; ANSWER SECTION: help.leavemealone.app. 0 IN CNAME help.leavemealone.com.

help.leavemealone.com. 0 IN CNAME leavemealone.helpkit.so.

leavemealone.helpkit.so. 0 IN CNAME helpkit-ssr.onrender.com.

helpkit-ssr.onrender.com. 0 IN CNAME helpkit-ssr.onrender.com.cdn.cloudflare.net.

helpkit-ssr.onrender.com.cdn.cloudflare.net. 0 IN A 216.24.57.3

helpkit-ssr.onrender.com.cdn.cloudflare.net. 0 IN A 216.24.57.253

[ Parent | on HN ]

Re:GitBook bypassing Cloudflare DNS to route traffic to thei... by jivings on Wednesday November 23, 2022 @01:32AM (#33715920)

Yes. DNS shows it should be redirecting to leavemealone.helpkit.so but it actually redirects to dinkydani.gitbook.io

[ Parent | on HN ]

Re:GitBook bypassing Cloudflare DNS to route traffic to thei... by bauruine on Wednesday November 23, 2022 @02:10AM (#33716122)

help.leavemealone.com. is a CNAME to leavemealone.helpkit.so which again is a CNAME to helpkit-ssr.onrender.com. and so forth till you get the A records. Your browser then connects to that IP and there you get the 302 redirect. I'm still not sure what I should see here.

EDIT: This is a CNAME chain and although it's not recommended it's valid https://serverfault.com/a/309660

[ Parent | on HN ]

Re:GitBook bypassing Cloudflare DNS to route traffic to thei... by jivings on Wednesday November 23, 2022 @02:22AM (#33716194)

The A records that you've gotten to are unrelated to Gitbook and there are no 302 redirects on our side. As far as I understand it's some internal redirect happening in Cloudflare's network.

You can read more info here: https://community.cloudflare.com/t/dns-subdomain-no-longer-w...

[ Parent | on HN ]

Re:GitBook bypassing Cloudflare DNS to route traffic to thei... by bauruine on Wednesday November 23, 2022 @03:03AM (#33716431)

Thanks for the explanation. I still don't know exactly what's going on here. How do the DNS records look on the Cloudflare UI?

[ Parent | on HN ]

Re:GitBook bypassing Cloudflare DNS to route traffic to thei... by jivings on Wednesday November 23, 2022 @03:54AM (#33716729)

help.leavemealone.app -> CNAME -> help.leavemealone.com -> CNAME -> leavemealone.helpkit.so

Gitbook is nowhere in the chain

[ Parent | on HN ]

Re:GitBook bypassing Cloudflare DNS to route traffic to thei... by bauruine on Wednesday November 23, 2022 @04:04AM (#33716798)

Then you have to ask helpkit.so why they are using render.com to do the redirect.

[ Parent | on HN ]

Re:GitBook bypassing Cloudflare DNS to route traffic to thei... by bauruine on Wednesday November 23, 2022 @04:29AM (#33716981)

But it's hitting their DNS zone and they have decided to add a CNAME to helpkit-ssr.onrender.com for leavemealone.helpkit.so.

[ Parent | on HN ]

Re:GitBook bypassing Cloudflare DNS to route traffic to thei... by jivings on Wednesday November 23, 2022 @04:24AM (#33716939)

The request is never hitting HelpKit's servers.

[ Parent | on HN ]

Re:GitBook bypassing Cloudflare DNS to route traffic to thei... by bauruine on Wednesday November 23, 2022 @01:32AM (#33715917)

The domains resolves to an IP announced by AS397273 (https://render.com/) the web server at this IP returns a 302 redirect to https://dinkydani.gitbook.io/leave-me-alone-help/. What exactly can I see here?

[ Parent | on HN ]

Re:GitBook bypassing Cloudflare DNS to route traffic to thei... by jivings on Wednesday November 23, 2022 @01:52AM (#33716017)

Try doing a curl on the domain that's returned by the CNAME and comparing it to a curl on the original URL. I agree it makes no sense so I don't blame you for assuming it's nonsense.

There's a redirect happening somewhere but it ain't from the web server listed on the DNS record.

[ Parent | on HN ]

Re:GitBook bypassing Cloudflare DNS to route traffic to thei... by zupa-hu on Wednesday November 23, 2022 @03:50AM (#33716700)

I agree with @aussiedude that I don't see anything suspicious.

Authorative A records:

# help.leavemealone.app

help.leavemealone.app. 60 IN CNAME help.leavemealone.com.

# help.leavemealone.com

help.leavemealone.com. 30 IN CNAME leavemealone.helpkit.so.

# leavemealone.helpkit.so

leavemealone.helpkit.so. 1799 IN CNAME helpkit-ssr.onrender.com.

# helpkit-ssr.onrender.com

helpkit-ssr.onrender.com. 300 IN CNAME helpkit-ssr.onrender.com.cdn.cloudflare.net.

# Authorative A records for helpkit-ssr.onrender.com.cdn.cloudflare.net:

helpkit-ssr.onrender.com.cdn.cloudflare.net. 300 IN A 216.24.57.3 helpkit-ssr.onrender.com.cdn.cloudflare.net. 300 IN A 216.24.57.253

Indeed opening the page loads 216.24.57.3 where I get a HTTPS response with statusCode 302 that redirects to -> https://dinkydani.gitbook.io/leave-me-alone-help/

Seems to be what should happen?

ps - I'm stunned though to see 4 CNAMEs, especially with 60 and 30s TTLs

[ Parent | on HN ]