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Questions tagged [denial-of-service]

Denial of Service is a family of attacks that attempt to force a target to use up resources (CPU time, memory, bandwidth etc) through flood a target with useless packets, connections or tasks

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37 views

Types of firewalls to implement to reduce DoS attacks in POS systems

Would you need an internal, external and a host-resident firewall for each POS client?
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1answer
56 views

Nginx: mod-security rule for http slow DoS attack

The only related rule in mod-security for slow DoS is modsecurity_crs_11_slow_dos_protection, and it's for Apache only. Is there a rule for Nginx?
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43 views

Addressing availability element of CIA triad using technical controls

When looking at the availability element of the CIA triad, most definitions mention that availability is addressed through ensuring system up-time by using controls such as disaster recovery, business ...
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1answer
433 views

Is there a multi-layered DoS protection which can be tightly integrated with cloud hosting services?

I know that one can deny services (DoS) in any of the 7 layers of the OSI model and that in principle, a denial can be done by a single entity (human or machine) or from 2 or more such entities ("...
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2answers
41 views

Account lockout to protect from brute force: doesn't it open up vulnerabilities to DOS attacks? [duplicate]

AFAIK the recommended practice to mitigate brute force attacks is to lock an account down for, say, 15 min (perhaps escalating lockout time if the attack continues afterwards?) after, say, 5 failed ...
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59 views

How to identify a Ping of Death attack by analyzing its packet in Wireshark? [closed]

I've tried researching it for a long while, but came out dry.
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1answer
47 views

Are NTP servers without monlist still dangerous?

I've been studying DOS flood attacks, namely NTP and DNS floods. I know that monlist is the primary factor in launching these sorts of attacks, but I have one question. The problem is are these ...
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3answers
2k views

Threshold for DDOS Attack

I am trying to understand and simulate SYN Flood DDOS attacks. I am using snort to give me alerts. While I have control over the rate for my testing, I am interested in knowing what a good estimate of ...
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0answers
46 views

How is satellite uplink secured from DOS attack?

How satellite communication is secured from Denial of Service attack on up-link frequency as anyone can create interference?
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47 views

DoS attack? Can't figure out what they were up to

I have two web servers, firewalled, using one-to-one NAT to two static IPs. The other day I noticed a slowdown, so I tailed the firewall log to see what was happening. It showed some kind of attack ...
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1answer
481 views

Is Mailbait still a threat?

Is Mailbait (or similar services) still a threat, was it ever a threat, and if so how can it be mitigated? Mailbait is that service that promises to fill up your email inbox by sending you a huge ...
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4answers
493 views

Most reduced types of DoS attacks

As I understand it, there are generally only two common types of Denial of Service attacks in regards to the OSI model: Network-Layer-DoS (NLDoS) on layers 3, 2 or 1. Application-Layer-DoS (ALDoS) on ...
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3answers
136 views

Is a DoS attack possible on a single home connection when the ISP uses NAT?

Today almost all ISPs use a NAT system to assign more people the same IP (at least where I am), probably because the IPv4 addresses are ending and they want to save money. Is it possible to make a DoS ...
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2answers
219 views

Why is DDOS is one of the most common Cyber-Attack? [closed]

Based on some articles and some research DDOS is one of the most common cyber-attack. There are tonnes of articles out there about the DDOS subject, including describing, mitigating, the question "...
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1answer
189 views

Difference between DNS flood attack and DNS amplifier attack [duplicate]

I am trying to understand DNS flood and DNS amplifier attack. I have read the definition and am still confused, could you give me an example of each attack or tell me the differences between them? It ...
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6answers
16k views

Is it safe to let a user type a regex as a search input?

I was in a mall a few days ago and I searched for a shop on an indication panel. Out of curiosity, I tried a search with (.+) and was a bit surprised to get the list of all the shops in the mall. I'...
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1answer
408 views

How perform Ping Flood, Ping Of Death, and Teardrop on local network?

Is it possible nowadays to perform a Ping Flood, Ping Of Death, and Teardrop on local network? According to this article, these three attack are useless and out of date. I'd like to test this on my ...
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3answers
244 views

How to detect a DoS attack if today all use network address translation?

If a basic DoS attack can be handled by limiting the number of connections that occur in a interval of time with one IP and some enterprises and institutions use network address translation with many ...
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29 views

Fully patched Windows 2008 immediate BSOD from low privilege account

Is there any exploit/script/vulnerability where a very low privileged user can trigger a BSOD or reboot? I'm familiar with the USB exploit, but I'm wondering if its possible with some remote method? ...
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1answer
218 views

How to avoid XML vulnerabilities in Python?

I am writing a suite of Python 3 applications (including first a command line utility, second an HTTP(S) proxy) which deal with XML. Today I've discovered that there are several vulnerabilities ...
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31 views

DoS Service on moxa EDR-810

I'm in the process of configuring a Moxa EDR-810 router. I've done no work with DoS before and I'm trying to get an understanding of what is happening. The router gives options for Xmas scan and a ...
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3answers
413 views

A way to prevent non distributed, network-level DoS attacks?

I have a DigitalOcean Ubuntu 16.04 machine with Bash as main shell, Nginx, PHP-FPM, and MySQL as server environment, Certbot for TLS and WordPress for web applications. I protect from MITMs with TLS. ...
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2answers
187 views

SYN-flood to the localhost Apache server

I've set up the apache server on localhost (127.0.0.1). I've downloaded PackETH to perform a DoS attack. So PackETH wants MAC-HEADER of the destination and source. And I don't know, where to find ...
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1answer
200 views

What do DoS/ DDoS TCP SYN Floods and Layer 7/HTTP floods look like on a firewall log?

I am looking for some examples of log files for DoS or DDoS attacks that show a SYN Flood or a HTTP/Layer 7 Flood. I have had a google, but can't seem to find anything. Would the incoming packet ...
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1answer
76 views

Protecting WordPress from a single machine DoS (either in network/web level)?

I use a DigitalOcean Ubuntu 16.04 machine with Bash, LEMP and WordPress. I already did the best I can to protect the system and WordPress from BFAs and Backdoors, and to protect WordPress from DB ...
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2answers
56 views

Is DDoS a specific type of ALDoS

In a very broad terminology: I understand Application Layer Denial of Service (ALDoS) to be a 1 machine on 1 machine attack. I understand Distributed Denial of Service DDoS (DDoS) to be a 2 or more ...
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1answer
102 views

Web application set cookie based on a GET paramater. Is it vulnerable?

In my web application I take the GET paramater x and I store it in a cookie after URL-encoding it (so there is no HTTP response splitting). Some people say that this can be abused to cause DOS, but I ...
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2answers
182 views

Depleted DB User Connections leads to DoS

I want to ask you for clarification and advice regarding the following situation that emerged during a penetration test of my client's eCommerce shop. My client is using an xt:commerce shop software ...
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2answers
160 views

Reverse DoS Attack [closed]

Is there anything on a computer or a router that prevents a hacker from doing a DoS on you. So let's say that you are going to https://www.google.com/. When you enter that in the search bar, it sends ...
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1answer
153 views

How to protect a website from DDoS without a CDN? [closed]

I have basic knowledge in Bash and with that knowledge I rented a remote machine in a mostly-self-managed hosting platform (DigitalOcean) and raised a LEMP environment on which I have a website. I ...
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0answers
344 views

How to determine DoS protection rates for firewall

I am looking to enable my Firewall's DoS protection, and when searching for values to put in the rate fields, am finding that the answer is usually "it depends". While there is almost always room for ...
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1answer
2k views

Difference between Amplification and Reflection Attack?

Reflection Attack: Reflection attacks are attacks that use the same protocol in both directions. The attacker spoofs the victim’s IP address and sends a request for information via UDP to servers ...
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2answers
62 views

Is it feasible to leverage DOS by triggering large numbers of application exceptions?

One key aspect of a DOS or DDOS seems to be to leverage the required computational power on the attackers side to maximize the impact on the target side. This wiki article lists many examples of such ...
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3answers
569 views

Does blocking an IP with IP Tables protect you from a DOS (not DDOS) attack?

I am fairly new to network security, and I just learned about the Fail2Ban framework you can use for automated exploit detection/prevention. It says that you can protect yourself from DOS attacks by ...
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0answers
151 views

DoS attack to device not connected to WiFi

I would like to know if there is any attack to DoS a device (NOT AN AP) that is not connected to any WiFi network. Using Probe Request frames I can obtain the MAC address. I can't 802.11 deauth ...
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1answer
91 views

What resources does a SYN flooding attack try to exhaust? [duplicate]

In a SYN flooding denial of service attack, what resource is the attacker trying to exhaust? RAM? CPU?
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1answer
159 views

Is ping of death attack specific to ICMP or could it also happen with other transport protocols?

A Ping of Death attack is a denial-of-service (DoS) attack, in which the attacker aims to disrupt a targeted machine by sending a packet larger than the maximum allowable size, causing the target ...
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2answers
289 views

How to whitelist an IP, but prevent others from DoS attacks [closed]

I've a Windows Server 2016 and I want to allow unlimited incoming requests from some specific IPs, but prevent others from DoS attacks. I see RDP Defender but I'm not sure how good or safe it is to ...
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1answer
402 views

DoS testing as a part of penetration testing

I am doing penetration testing on web application in my local network. As a part of testing procedure I am planning to perform DoS testing. Because I am using just one PC I think that the only ...
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1answer
306 views

Can someone help me decipher what these netgear log entries mean? Am I getting hacked?

Can someone help me decipher what these log entries mean? Am I getting hacked? So this is my residential router is a netgear gateway C3700-100NAS with Spectrum Internet. Usually I have no problems. ...
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1answer
148 views

Does SMS flood cause denial of service even when “blocked”?

Imagine a SMS flood using a few phone numbers. The client blocks the phone numbers using the build in mechanism of the smart phone, and thus does not receive any notifications. Even though the user ...
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1answer
57 views

Most resource intensive assembly instructions? [closed]

Assuming I want to overload a server which is running some kind of web-app or gaming server, what is the best way for me to figure out which usage of legitimate features on the web-app or gaming ...
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2answers
366 views

SSH protocol banner is a kind of DOS?

In my test environment with Python script I generate on a target server: SSHException: Error reading SSH protocol banner simply opening/closing a sufficient number of ssh connection. Is it ...
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2answers
140 views

The difference between DDoS attacks in the cloud computing and the traditional network infrastructure [closed]

Is there any difference between the DDoS attack in the cloud computing and traditional network in infrastructure? What are the important features for detection these types of attack in cloud ...
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2answers
401 views

Apache Access Log Indicates DOS Attack? Or any other attack? [duplicate]

Below is my apache access log. 175.139.240.59 - - [28/Jul/2017:23:42:50 +0000] "HEAD http://xx.xxx.xx.xxx:80/mysql/admin/ HTTP/1.1" 301 - ... 175.139.240.59 - - [28/Jul/2017:23:42:50 +0000] "HEAD ...
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1answer
1k views

DeAuth sent to router doesn't deauthenticate

I'm trying to perform a De-authentication attack on my wifi network. My command is: aireplay-ng -0 0 -a B8:A3:86:5E:9C:DC wlan0 The response looks like this: 20:35:59 Waiting for beacon frame (...
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4answers
561 views

How to prevent “TSource Engine Query” DDoS attack?

I recently started a game hosting company and one of my boxes is being hit very hard by what i believe is a botnet. We are getting thousands of IP addresses sending traffic to a port where a game ...
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2answers
144 views

How Can Someone Do A Denial Of Service Attack With JavaScript

I was recently reading this cloudfare article about JavaScript Denial Of Service and I didn't understand how it could work. From what I've learned JavaScript is a client side language and can't ...
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4answers
249 views

What damage can a MITM do to encrypted traffic, and what can be done about it?

Assume a server and a client that are each on physically secure, uncompromised networks. However, between each network is an attacker that is capable of viewing traffic. For example, two department ...
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0answers
330 views

Memory and CPU usage during a denial of service attack. How to understand the data?

The Debian crontab file that is a web server Apache has the line: */2 * * * * echo -e "`date`\n\n`free` \n\n`vmstat`\n" >> /home/hacker/free_vmstat_output.txt I ...