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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

5
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2answers
226 views

Why were hyperlink auditing pings used for DDoS attacks and not any other requests?

A few days ago this new story has been published: Researchers have found that the HTML feature called hyperlink auditing, or pings, is being used to perform DDoS attacks against various sites. This ...
2
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0answers
128 views

WiFi Channel 6 unusable, but no other AP on Channel 6

There is a single MAC address broadcasting a vast amount of QoS packets on channels between 3 and 9. Is this a DoS attack? The access point that MAC address is associated with says its on channel 1. ...
0
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1answer
33 views

Question about hping3, TCP and ngrok

I have set up a experimental setup which consists of: Windows PC with ethernet cable; Arduino shield (connected to Windows machine with USB) with LTE connectivity sending data using TCP/IP to ngrok; ...
0
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1answer
34 views

Can a process be DoSed by interfering with its compare-exchange loops?

Consider a file accessed by multiple processes; the processes map the file to memory and then use lock-free operations to synchronize (for example, use atomic-add to allocate an offset in the file to ...
0
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1answer
73 views

Detect / Prove and Prevent Wifi Deauth attack

I'm suspecting that my neighbor is running multiple Wifi deauth flood attacks against my Wifi. I'm using WPA2 and I don't think he can really crack my password, but my devices keep having wifi ...
0
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0answers
143 views

Snort rule for syn flood attacks - Limiting number of alerts

So I have a snort rule that detects syn flood attacks that looks like this: alert tcp any any -> $HOME_NET 80 (msg:”SYN Flood - SSH"; flags:S; flow: stateless; detection_filter: track by_dst, ...
0
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0answers
49 views

Can jumping to a new SSID be a solution for flood attacks?

If an attacker can access inside my network in any way and make a UDP or ICMP flood attack on any point of the network (server, client or router), can I prevent this attack transiently with jumping on ...
1
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1answer
98 views

Is this regular expression vulnerable to DoS?

FindBugs flagged the following email address validation regex as vulnerable to DoS: ^[\w!#$%&'*+/=?`{|}~^-]+(?:\.[\w!#$%&'*+/=?`{|}~^-]+)*@(?:[a-zA-Z0-9-]+\.)+[a-zA-Z]{2,6}$ Here's an easier ...
0
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0answers
24 views

Does limiting the length of a password help prevent DoS attacks? [duplicate]

I was told that you can DoS a server with unlimited password length because of the time that it would take to hash it. But isn't the password hashed on the client's side before leaving the user's ...
2
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4answers
264 views

What is the difference between an SYN-Flood attack and an SYN-ACK-Flood attack?

What is the difference between an SYN-Flood attack and an SYN-ACK-Flood (SYN Reflection) attack?
57
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7answers
12k views

Does it make sense to consider a triggerable server software crash a DOS attack?

I've found a little vulnerability in a web application running on Node.js server. It works by sending some crafted payload to the application server, which makes the application server code to throw ...
1
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2answers
71 views

Risk and probability from CVE

How can I find risk and probability from CVE (https://cve.mitre.org/)? I read an article and it says (pg 14), The cost is derived from the attack tree, and risk and probability are based on CVE ...
0
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1answer
94 views

How fill up a gig interface bandwidth with hping3?

I've been trying to test our software against DOS attacks. So, I used 'HPing3' but it just fills up 10-11M of my interface's bandwidth! I ran the tool 40 times, I mean 40 hping3 processes, ...
1
vote
1answer
44 views

lan-side denial of service affecting target's CPU performance

Why does a LAN-side UDP flood take up the target's CPU resources and make it sluggish? i.e: the mouse doesn't respond properly, opening an application is slow... Note: The computers are both ...
0
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1answer
63 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?
1
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1answer
205 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?
1
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1answer
54 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 ...
2
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1answer
448 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 ("...
2
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2answers
118 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 ...
0
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1answer
288 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.
0
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1answer
118 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 ...
4
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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 ...
2
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0answers
55 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?
2
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1answer
2k 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 ...
6
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4answers
564 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 ...
3
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3answers
228 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
231 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 "...
2
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1answer
462 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 ...
90
votes
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'...
1
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1answer
1k 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 ...
1
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3answers
617 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 ...
0
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0answers
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? ...
1
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1answer
364 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 ...
0
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0answers
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 ...
7
votes
3answers
438 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
272 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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2answers
319 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 ...
2
votes
1answer
87 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 ...
1
vote
2answers
57 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 ...
6
votes
1answer
105 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 ...
3
votes
2answers
187 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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votes
2answers
214 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 ...
3
votes
1answer
159 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 ...
9
votes
1answer
3k 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 ...
2
votes
2answers
64 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 ...
5
votes
3answers
693 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
183 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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votes
1answer
121 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?
3
votes
1answer
214 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 ...
1
vote
2answers
354 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 ...