How did an IP send Get requests to my code? - security

I am new to web development. I am developing a flask web server on my linode linux web server on port 5000. I got this output from an unknown ip. I researched the ip and found out that this is a whitelisted IP address and is "harmless", but I dont know. It looks like it sent GET requests to my cover photo, the javascript, the css, an icon on the page, and an unknown request. What does sending a GET request to these items even entail? I dont have any button or anything that sends a get request to these items. Whenever I am developing the web server while on port 5000 I am usually the only IP on the output. Additionally, this web server communicates with a raspberry pi over mqtt over the non-encrypted port 1883.
Again, I am new to this world and am wondering if anyone can help me decipher what this means that would be very helpful. In the meantime should I will configure the servers firewall to only allow requests from my computers ip to my server? Anyone think this is a reasonable next step or have any additional advice?

I believe what's happening is that your website is sending a GET request to retrieve those assets (e.g. your images) which are stored under your localhost address and the paths that you see in the console output.

Related

Node server :remote-addr displayed local IP (192.X.X.X) when accessed from python-requests

I have an express server that uses nginx and monitors the X-Forwarded-For header.
The node server has the following lines of code:
app.set('trust proxy', '127.0.0.1');
app.use(morgan(':remote-addr')); // and other info too
Normally, when users make requests, independent of the client (mobile app, scripts, etc.) the IP displayed is the remote one.
Recently, I have observed that someone tried to hack into my server using python-requests/2.22.0 and the remote IP was not his IP address, it was 192.X.X.X. I tried to reproduce this myself by accessing the server from itself, but the remote address (global server IP address) was displayed.
Can you better explain to me how this works and if this is something I should be worried about?
They never accessed your server through Nginx; check the logs. They sent a local connection header directly to the IP:port hosting your server. This could be damaging if your security policies are not set correctly, it could leak site IPs and potentially allow an attacker to have a free path into your server without response back and no limits.
As we get scarier, the user could initiate a BGP hijack and take over the relay points sending users to your server end-points; this is one to YouTube or google more about.
As we finish off, know most hosting companies allow for private networking and do give somewhat of a firewall to use but most users assume this is secure when it actually is not! These private networks connect you to the hundreds->thousands servers in a rack or zone. So if the attacker bought a server next to yours (which would likely be a bot) they could scan the private networks for some fun-time which is against TOS but the hosts don't check this good enough or secure it.
In your case, it sounds like the server is responding to the entire internet and bots are having a go at it; Try setting your Node.js server up as localhost only, at port 443 or whatever and host that through nginx. That way anytime someone inserts your IP or domain name it is forwarded by nginx to the local resource. Someone couldn't just use the IP + Node.js port and play games. If you do this, a user may still send the header with fake IP but it won't result to IP Leak, or anything bad unless that IP had super powers on your site, which no filter on your site should say 192.168.x.x gets ADMIN mode. You can feel confident.

Node.js only allow connections with specific VPN

I am trying to make a simple Node.js app with the express npm package to only allow if you are connected to a specific VPN. Here's an example:
I am connected to VPN exampleVPN and I am looking at http://localhost:8080, which sends me a 204 response.
But:
If I am not connected to exampleVPN and go to http://localhost:8080, I get a 401 response.
I'm just starting out and I am not sure of the strategy to go with here.
My first guess is to only allow incoming requests from a specific VPN server through a middleware by whitelisting the VPN's IP but that seems janky and could bring up some issues down the line if the VPN's IP changes for whatever reasons.
Thanks in advance.

IP address is not allowed for this token on API CALL

please bear with me, I am a newbie in integrating APIs and so I am encountering some issues that need help from experts. I am working on API that has only the server IP address whitelisted to access resources on it. However, I am working from my local PC in doing the integration. Now when I try accessing the API from the localhost, it tells me that my PC's IP address is not allowed for the token I am using. I have tried to do some google search on how to use the server's IP address from my PC and I have come across something called PORT FORWARDING. I have tried to figure out what it is but I am getting some difficulties setting it up on my PC. Could someone help me with any alternatives to making requests using my server's address from my PC? If not, I will appreciate it if someone could explain to me what port-forwarding is in layman's language and if possible through a reference. Thank you in advance. I am on Linux-mint
To make a request with your server's IP address, the request has to at least pass through your server. Setting up an temporary SSH "port forward" is the easiest way to do it. The following command opens an SSH session with your server machine, and for the duration of the session the ssh client will listen for connections on TCP port 8443 on your dev machine and the server will forward them to somewebsite.net:443.
ssh -L 8443:somewebsite.net:443 your.server.name
If you now send a request to https://localhost:8443 from Postman, SSH will tunnel the request to your server. The server will communicate with somewebsite.net on your behalf, and the request will have your server's IP address.
See longer discussion of this feature for example at:
https://www.ssh.com/ssh/tunneling/example
https://phoenixnap.com/kb/ssh-port-forwarding
This style of port forwarding is not without its problems though. You are using HTTPS, which includes protections against a "middle man" intercepting connections like this. You can get around this by disabling certificate verification. Another problem is that somewebsite.net may expect you to set the Host HTTP request header to "somewebsite.net", and it will be set to "your.server.name" instead.

node js send html to network rather than only localhost server

I'm using node js trying to send my web-page to my network, I successfully call localhost:port in my computer using express as server, the webpage loads fine trigger my webcam which I used to streaming in the webpage, and then im working to make a simple app in my phone to directly access my server, so my questions:
1.How do I able to access my server from different devices in the same wireless-network? by calling ip + port ?192.168.1.104:9001 ? cause i've tried and it didnt work.
2.I've found https with .pem something like that, is that the answer ? is there also any other way ?
3.maybe any advice before i work to make my web-app to devices? using koa? i don't even really know what is that, but i'm happily take any advices.
EDIT: i've read How could others, on a local network, access my NodeJS app while it's running on my machine?
let's say I simply using random router, so i can't configure my router-port, my server in my pc and my phone join in the same network, trying to access the server in my phone
1.How do I able to access my server from different devices in the same wireless-network?
All you need to do is find your server's IP address in this same wireless-network, and find the Node.js application's port. Then access the following URL in other devices:
http://{server_IP}:{port}
However, there are some points need to check:
Need to check firewall and confirm the port is not blocked, server IP is not blocked by test device, and test device IP is not blocked by server.
Need to check whether there is any Proxy setting in server and test device. If there is any, disable the proxy.
A computer may have many IP addresses at the same time, you need to find the correct one in the same wireless-network. For example, If you install a virtual machine software such as VMware and run a virtual system inside, your real computer will get IP address as 192.168.*.* -- this IP address looks like an intranet IP in wireless-network, but it is not, and can never be accessed by test device.
2.I've found https with .pem something like that, is that the answer?
No, HTTPS has nothing to do with this problem. HTTPS just add security (based on HTTP layer), it does not impact any HTTP connectivity. Actually, to minify the problem, it is better to only use HTTP in your scenario.
There is only one very special case that may bring your problem by HTTPS -- the test machine is configured and will block any non-HTTPS connection for security.
3.maybe any advice before i work to make my web-app to devices? using koa?
My suggestion is: As there is an HTTP connectivity issue, the first step is trying to find the root cause of that issue. Thus, it is better to make a simplest HTTP server using native Node.js, no Koa, no Express. In this way, the complexity of server will be reduced, which makes root cause investigation easier.
After the HTTP connectivity issue is fixed, you can pick up Koa or Express or any other mature Node.js web framework to help the web-app work.
4.let's say I simply using random router, so i can't...
Do you mean your server get dynamic IP address by DHCP? As long as the IP is not blocked by test device, it does not matter.

How to setup an API server with no domain name

I've been struggling to understand this because I don't quite know what to search for. Basically, I'm working on a simple node server that just works as an API that is to be consumed by a mobile application. I'm planning to deploy it to DigitalOcean but since I don't need a domain name because I don't have a website, how will I send the HTTP requests to the server? My guess is something related to the droplet's IP but that doesn't seem quite right.
Just send requests to IP address and port from your mobile app. like GET http://54.54.32.23:3000/user-newsfeeds/15

Resources