When a normal TCP connection starts, a destination host receives a SYN (synchronize/start) packet from a source host and sends back a SYN ACK (synchronize acknowledge). The destination host must then hear an ACK (acknowledge) of the SYN ACK before the connection is established. This is referred to as the "TCP three-way handshake."
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There are several general categories of DoS attacks. Some groups divide attacks into three classes: bandwidth attacks, protocol attacks, and logic attacks. Following are brief descriptions of some common types of DoS attacks.
In this paper, we describe and analyze a network based DoS attack for IP based networks. It is known as SYN flooding. It works by an attacker sending many TCP connection requests with spoofed source addresses to a victim's machine. Each request causes the targeted host to instantiate data structures out of a limited pool of resources to deny further legitimate access.
The paper contributes a detailed analysis of the SYN flooding attack and existing and proposed countermeasures. SYN flooding attacks in application Performance Validation with VoIP gives improper results. To overwhelm it, IPv6 approaches have been proposed here with successful implementation it with Network Tester using Moonerv6 Phases algorithms. Agilent Network Tester practices on the same principles to make availability of IPv6 service in Networks or sensor networks.
Today in Hacks From Pax we'll talk about AIDE, a host intrusion detection system. AIDE can provide another important layer of security for a system, specifically a layer designed not to keep intruders out per se, but to notify administrators of a possible compromise or intrusion. By itself it won't prevent a successful intrusion, but it can help prevent the only thing worse: a successful intrusion that you don't know about yet.
Guardian Digital is pleased to announce the release of EnGarde Community v3.0. This release represents the most significant number of improvements since the first version released more than four years ago.
If you haven't tried EnGarde recently, then I'm certain you'll be equally as excited about this release as we are. Completely redesigned web interface, firewall functionality, integrated Security-Enhanced Linux protection, and completely free updates are just a few of the outstanding new benefits.
An article on "Security Problems in the TCP/IP Protocol Suite" by S.M.Bellovin in 1989 initially explored IP Spoofing attacks . He described how Robert Morris, creator of the now infamous Internet Worm, figured out how TCP created sequence numbers and forged a TCP packet sequence.
Today on Hacks From Pax we'll be discussing PHP web application security. PHP is a great language for rapidly developing web applications, and is very friendly to beginning programmers, but some of its design can make it difficult to write web apps that are properly secure. We'll discuss some of the main security "gotchas" when developing PHP web applications, from proper user input sanitization to avoiding SQL injection vulnerabilities.
Five years after our original interview with Brian Gemberling, founder of PullthePlug.org, we catch up with Daniel Alvarez and the rest of the site's administrative management. Its structured management and focus on the community will ensure many years of continued success. You're asking, what is pull the plug? Read more to find out...
Greetings, gentle reader, and welcome to linuxsecurity.com and our new recurring series of articles on security related mistakes and how to avoid them. I'm your host, Pax Dickinson, and today we'll be reviewing basic Linux file and directory permissions and how to avoid some common pitfalls in their use, in this episode of Hacks From Pax.
In a word, No. No machine connected to the internet is 100% secure. This doesn't mean that you are helpless. You can take measures to avoid hacks, but you cannot avoid them completely. This is like a house — when the windows and doors are open then the probability of a thief coming in is high, but if the doors and windows are closed and locked the probability of being robbed is less, but still not nil.
Welcome to the first tutorial in the 'Getting to Know Linux Security' series. The topic explored is Linux file permissions. It offers an easy to follow explanation of how to read permissions, and how to set them using chmod. This guide is intended for users new to Linux security, therefore very simple. If the feedback is good, I'll consider creating more complex guides for advanced users. Please let us know what you think and how these can be improved. If you have ideas for future topics, please post them in the discussion forum below.
The Tao of Network Security Monitoring is one of the most comprehensive and up-to-date sources available on the subject. It gives an excellent introduction to information security and the importance of network security monitoring, offers hands-on examples of almost 30 open source network security tools, and includes information relevant to security managers through case studies, best practices, and recommendations on how to establish training programs for network security staff.
This brief article outlines the history and story behind Linux Netwosix, a security-focused distribution that is still in early stages of development. Vincenzo Ciaglia, its Italian founder, gives the Linux community an update on how the project has progressed after 11 months.