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Questions tagged [ddos]

"A distributed denial of service attack (DDoS) occurs when multiple systems flood the bandwidth or resources of a targeted system, usually one or more web servers."

559 questions
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Prevent Malicious Requests - DOS Attacks

I'm developing an asp.net MVC web application and the client has request that we try our best to make it as resilient as possible to Denial of Service attacks. They are worried that the site may receive malicious high volume requests with the…
Leigh Ciechanowski
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How can I defend against DoS attacks using Amazon EC2 Load Balancer?

We usually blacklist IPs address with iptables. But in Amazon EC2, if a connection goes through the Elastic Load Balancer, the remote address will be replaced by the load balancer's address, rendering iptables useless. In the case for HTTP,…
netvope
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Which cloud based, scalable web service is best for DDOS prevention?

I have an idea for a website that I would like to develop and release. It is a web application that I would like to implement on some form of cloud-based web hosting service (i.e. the Google App Engine, Amazon Web Services, others that I may not be…
RLH
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Dealing with CloudFlare's: cf_chl_jschl_tk & cf_chl_captcha_tk?

The problem: When my website is set to "I'm under attack" mode, once a user passes the CloudFlare screen they are redirected to my website with a large, and rather long query get…
Jack
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2 answers

Apache2 mod_evasive vs mod_security with OWASP crs when protecting against DDOS?

Good day, I'm running an Apache2 server in front of a Tomcat and I need to implement a DDOS protection mechanism on the Apache2 layer. I have two candidates: mod_evasive and mod_security2 with the OWASP core rule set. Mod_security is already…
Martynas Sušinskas
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2 answers

DDOS in Cloud Run

I am currently running two containers on Cloud Run for my web app (React and Nodejs). I have been looking into how to prevent my apps from DDOS. Any suggestion?
Communitarian
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Weird socket.io behavior when Node server is down and then restarted

I implemented a simple chat for my website where users can talk to each other with ExpressJS and Socket.io. I added a simple protection from a ddos attack that can be caused by one person spamming the window like this: if…
good_evening
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4 answers

How to limit the number of characters read by StreamReader.ReadLine() in .NET?

I am writing a web server application in C# and using StreamReader class to read from an underlying NetworkStream: NetworkStream ns = new NetworkStream(clientSocket); StreamReader sr = new StreamReader(ns); String request = sr.ReadLine(); This…
Roman Shumikhin
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4 answers

How can I set AWS ELB block too many queries from a given IP?

We have had issues where one IP makes hundreds of requests to our servers, resulting in an overloaded RDS database. Is there a way to set our AWS ELB to block in the case of this DOS-like behavior?
william tell
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How to share rate limiting state between traefik instances?

My company runs a kubernetes setup with 6 nodes and traefik 1.6 deployed as a DaemonSet to each node in production. Each traefik instance takes incoming (ssl terminated) requests on port 80 from an AWS ALB and forwards them to the individual…
fruuf
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1 answer

How to prevent SSDP reflection / amplification attacks correctly?

I'm implementing a device that ought to respond to SSDP M-SEARCH queries. I'm a device vendor and I don't have control where these devices will be deployed. There's a known DDoS attack that uses SSDP search amplification, that is attacker sends…
Dima Tisnek
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3 answers

Dealing with / preventing potentially malicious requests (AWS, Node.js)

I have a server that is running on aws - it's load balanced to some ec2 instances that run node.js servers. The security groups are set up so that only the LB can hit them on the HTTP port. I was tailing some log files, and saw a bunch (50 or so at…
Jesse
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Config of nginx to filter http flood

A have a http flood on my server, not so much queries, but anyway. Queries in log 95.55.237.3 - - [06/Sep/2012:14:38:23 +0400] "GET / HTTP/1.0" 200 35551 "-" "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US)" "-" | "-" 93.78.44.25 - -…
kedoff
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How to prevent DOS attacks on my http server which written in node.js?

using node.js, the net module for building a tcp server which can hande http requests. I would like to prevent dos attacks so what I have done is somthing like this: if (status.numOfCurrentRequests + 1 >= MAX_NUM_OF_CONNECTIONS) { socket.end(); …
0x90
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Using mod_evasive on a specific directory

I'm trying to limit requests to an API on an internal site I've managed to implement mod_evasive to successfully block requests after a specific amount in a specific time. But this is causing problems for users of the webUI I've tried limiting the…
hipyhop
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