I am running this docker image: https://github.com/nextcloud/docker with a cloudflare tunnel, meaning the webserver would see all the traffic coming from a single ip in 172.16.0.0/12 .

The documentation says:

The apache image will replace the remote addr (IP address visible to Nextcloud) with the IP address from X-Real-IP if the request is coming from a proxy in 10.0.0.0/8, 172.16.0.0/12 or 192.168.0.0/16 by default

So I thought that this is a not a problem, as other docker images can also automagically figure out the real IP address from traffic coming from cloudflare tunnels.

In the beginning it worked fine, then it was SLOW. Like 2 full minutes to load new feeds on news, waiting ages to complete a sync, and so on. I rebooted the server on those instances, and then it worked fine for a day.

So because at the time i was running it on unraid, i blamed the lag on that OS + my weird array of HDDs with decades of usage on them. Migrated to debian on a nvme array and… same lag!

Wasted hours trying to use caddy+fpm instead of apache and it’s the same, worked fine for a day, then it was slow again.

Then I wondered: what if the program is “smart” and throttles it by itself without any warning to the admin if it thinks that an ip address is sending too many requests?

Modified the docker compose like this:

  nextcloud:
    image: nextcloud

became

  nextcloud:
    build: .

and I created a Dockerfile with

FROM nextcloud
RUN apt update -y && apt upgrade -y
RUN apt install -y libbz2-dev
RUN docker-php-ext-install bz2
RUN a2enmod rewrite remoteip
COPY remoteip.conf /etc/apache2/conf-enabled/remoteip.conf

with this as the content of remoteip.conf

RemoteIPHeader CF-Connecting-IP
RemoteIPTrustedProxy 10.0.0.0/8
RemoteIPTrustedProxy 172.16.0.0/12
RemoteIPTrustedProxy 192.168.0.0/16
RemoteIPTrustedProxy 173.245.48.0/20
RemoteIPTrustedProxy 103.21.244.0/22
RemoteIPTrustedProxy 103.22.200.0/22
RemoteIPTrustedProxy 103.31.4.0/22
RemoteIPTrustedProxy 141.101.64.0/18
RemoteIPTrustedProxy 108.162.192.0/18
RemoteIPTrustedProxy 190.93.240.0/20
RemoteIPTrustedProxy 188.114.96.0/20
RemoteIPTrustedProxy 197.234.240.0/22
RemoteIPTrustedProxy 198.41.128.0/17
RemoteIPTrustedProxy 162.158.0.0/15
RemoteIPTrustedProxy 104.16.0.0/12
RemoteIPTrustedProxy 172.64.0.0/13
RemoteIPTrustedProxy 131.0.72.0/22
RemoteIPTrustedProxy 2400:cb00::/32
RemoteIPTrustedProxy 2606:4700::/32
RemoteIPTrustedProxy 2803:f800::/32
RemoteIPTrustedProxy 2405:b500::/32
RemoteIPTrustedProxy 2405:8100::/32
RemoteIPTrustedProxy 2a06:98c0::/29
RemoteIPTrustedProxy 2c0f:f248::/32

and now because nextcloud is seeing all the different ip addresses it doesn’t throttle the connections anymore!

  • @rufus@discuss.tchncs.de
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    10 months ago

    I tried to look it up but I wasn’t very successful. What they do in their free tier keeps being a mystery to me. In the $20/month is the the core ruleset from ModSecurity. I don’t need to pay them $20 to deploy that for me, the dataset is free and publicly available. I’ve just installed it on my VPS… It’s only a few lines in Nginx to enable that.

    And what you’re talking about is $200 a month. I seriously doubt anyone here uses that plan for their homeserver. I wouldn’t pay $2400 in a year for it.

    I still don’t get how that would work. Sure you can filter spam that way. And migitate attacks while the worst wave washes through the net. Or do machine learning and find out if usage patterns change. But how would it extend to 0-days faster than the software gets patched? This sounds more like snake-oil to me. If someone finds a way to inject something into a Nextcloud plugin and change things in the database so they have access… And then they do it to 100 cloudflare customers… How would Cloudflare know? If it’s a 0-day, they -per definition- don’t know in advance. And they’re just WAF, they don’t know if a user is authorized by mistake or if they’re supposed to have access. And they don’t know anything about my database, since it runs on my machine. And they also don’t know about the endpoints of the software and which request is going to trigger a vulnerability unless this manifests in some obvious (to them) way. Like 100 machines immediately start blasting spam through their connection and there is one common request in the logfiles. Otherwise all they can do is protect against known exploits. Maybe race the software vendor and filter things before they got patched. I just don’t see any substantial 0-day protection that extends to more than “keep your server up to date and don’t use unmaintained software.” Especially not for the home-user.

    • chiisanaA
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      110 months ago

      The free tier rolled out was specifically to address upstream vendors patching Log4J too slowly. They’re able to monitor the requests and intercept malicious patterns before it hits the server running unpatched (due to upstream unavailable yet) applications. They are updating with more rules for the free tier set as far as they’ve stated. The extras from paid tiers are more extra rulesets and more analytics around what was blocked etc.

      At the end of the day though, you do you; the benefit for me may not be benefit for you. I’m not selling their service, and have no benefit what so ever should anyone opt into their services.

      • @rufus@discuss.tchncs.de
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        10 months ago

        Thx for explaining. I think I halfway know what this is about now. I don’t think I’m their target group. But I learned something about web application firewalls in the process and that is a good thing. I think I’m going to activate that for some of my private services since it’s so easy and look up if there are good ip ban lists. It’s a bummer that I don’t get to see proper documentation on this, since security is all about exact facts and scenarios. But I guess no answer is also an answer. If they just feed buzzwords to me, either my initial skepticism was warranted, or I’m just not their target audience and they only target enterprise users. Either way I’m better off with my current approach. I appreciate I got to learn something :-)

        • chiisanaA
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          310 months ago

          No problem! I appreciate the civil discussion! Thank you!