Denial of service attack, is an attempt through some means to make a computer or network resource unavailable.

learn more… | top users | synonyms (1)

0
votes
3answers
469 views

Measure bandwidth by client IP in realtime

I have been recently attacked using DoS attack on random ports. I wasn't able to get the attackers IP and now I would like to find it. What tool can show me bandwidth (in Kbits/Mbits) used by each ...
1
vote
2answers
386 views

Block packets based on length

Can I block packets (Specifically UDP) that are > X length? I am getting attacked exclusively by UDP packets that are very large in size from a large number of IP Addresses. I have a legitimate use ...
0
votes
2answers
27 views

Large request body DoS attacks - is this really much of a concern?

Can anyone explain why limiting the maximum request body size is useful for preventing DoS attacks? ModSecurity defaults to 1MB for example with SecRequestBodyNoFilesLimit. I guess I'm wondering ...
0
votes
2answers
286 views

iptables logs but doesn't drop packets

I am trying to create some simple iptables DOS protection rules for my web server. I was doing testing on the following rules: iptables -N LOGDROP > /dev/null 2> /dev/null iptables -F LOGDROP ...
3
votes
1answer
233 views

Buffer-stuffing denial-of-service attack

I started seeing this odd sort of effect that resembles denial-of-service attack against a Linux server. The effect is that the network becomes at least partially unusable very much the same as what ...
2
votes
1answer
814 views

DoS - Apache threads hanging when not receiving TCP ACKs after sending HTTP response

In summary, I had a case where all Apache threads were hung because all of them were waiting for a TCP ACK from clients after having sent the HTTP page, and because of that, the Apache threads were ...
1
vote
1answer
91 views

Can't figure out this attack, getting botnets and something else

About two months ago a site of mine started getting some sort of attack, and after further investigation I found it to be botnet zombies and something else which I can't figure out. My site is not ...
1
vote
1answer
75 views

What is idea of web server attack on thinker/js/think.js?

My web server is getting a lot of GET request on thinker/js/think.js and thinker/showSimilarInfo.do. These requests obviously constitute a server attacks. What is point of these attacks? Also, ...
0
votes
1answer
86 views

How does CT_LIMIT (the csf firewall setting) work?

I've been wondering if the csf firewall counts the connections for the last CT_INTERVAL seconds and then compares them to the CT_LIMIT value, or it just counts the current (at the moment) connections ...
0
votes
1answer
121 views

Should I expect reception of packets in hping3 --flood?

I'm testing a newly purchased VPS for DDoS vulnerability using hping3. If I do not use --flood, everything goes fine and I see close to 0% packet loss every time. But If I do use --flood, then the ...
0
votes
1answer
437 views

Mod_evasive not blocking a DOS attack using HEAD requests

Using Apache/2.2.15 on RHEL6 with mod_evasive config: DOSHashTableSize 3097 DOSPageCount 14 DOSPageInterval 2 DOSSiteCount 70 DOSSiteInterval 1 DOSBlockingPeriod 60 ...
0
votes
1answer
870 views

Windows Server 2008 Denial of Service Detection

We have a Windows 2008 server that hosts a file share in which a SQL server database is stored and accessed from another SQL server on the same network. Periodically, the database become inaccessible ...
-1
votes
1answer
34 views

How to duplicate a DoS attack

I've a WP blog who have received a DoS attack last days. server start using all CPU and memory, and eventually stop replying http request. It's a POST request to xmlrpc.php, I've checked the content ...
1
vote
0answers
44 views

Multiple IPs for one server to switch it in case of DoS / DDoS?

I'll run a server to secure a blockchain network (many servers with exposed IPs - no domains!). There will be only SSH, Fail2Ban, UFW, MONIT and the needed blockchain-client running on the server. ...
1
vote
0answers
572 views

How To Protect Tomcat 7 Against Slowloris Attack

I'm using Apache Tomcat 7 to run my webapp on Linux. I scanned it by Acunetix and it's telling me that my webapp is vulnerable to "Slow HTTP Denial of Service Attack". How can I protect it? Acunetix ...
1
vote
0answers
90 views

Cause for large number of duplicate web requests

I am seeing odd traffic to my web site. On occasion, probably a few times a day, I will get a flurry of requests for the same URI from the same IP address for several minutes, at rates from maybe one ...
1
vote
0answers
105 views

Preventing NFS Denial of Service

I have a NFS4 server running Ubuntu 10.04 Server, on an enterprise environment with 50+ clients. Overall, everything works fine, but from time to time, some client starts making +1000 NFS operations ...
0
votes
0answers
16 views

Protect a static website on Google Cloud Storage from DoS attacks

Is it possible to protect a static website on Google Cloud Storage from DoS attacks? I'm afraid such attacks might increase network egress cost.
0
votes
0answers
22 views

DNS using GRE work 50%

l'm in a big issue here to make it work I'm already at least about 60% done, but it is difficult and I would like to count on the help guys here who may have already done this type of configuration. ...
0
votes
0answers
110 views

Hold F5 cause all virtual hosts crash : How to limit max process per user in SuPHP

I am hosting a VPS server with Apache2, PHP/SuPHP and MySQL (LAMP). I have many virtual hosts on that server. The problem is that when someone (that happens about 20 times a day) hold F5 on a website ...