1.Unauthorized access—A network intruder can gain unauthorized access to networking devices through a variety of means, three of which are as follows:
Physical—If attackers have physical access to a machine, more often than not, they will be able to get in. The techniques used to gain access range from accessing the device via the console to physically taking apart the system.
System—System access assumes that the intruder already has a user account on the system. Proper privileges should be granted to the user such that he or she is authenticated and authorized only to do that which is deemed to be a function of his or her job duties.
Remote—Remote access involves intruders who attempt to penetrate the system remotely from across the Internet, through a dial−up connection, or on local or wide area network. This type of intruder usually has no account privileges.
2.Eavesdropping—Eavesdropping is used to capture TCP/IP or other protocol packets, thus allowing the intruder to decode the contents of the packet using a protocol analyzer. "Packet sniffing" is a more common term used to describe the act of eavesdropping. Eavesdropping leads to information theft, like stolen credit card and social security numbers.
3.Data manipulation—Data manipulation is simply the act of altering files on computers, vandalizing a Web site, or replacing FTP files.
4.Protocol weakness—The most−used protocol in circulation today is TCP/IP. This protocol was designed a long time ago. As a result, a number of its design flaws can lead to possible security problems, such as smurf attacks, IP spoofing, TCP sequence number prediction, and SYN floods. The IP protocol itself is a very trusting protocol; therefore, hackers are free to forge and change IP data.
5.Session replay—Intruders can eavesdrop on one or more users involved in a communication session and manipulate the data in such a manner according to the hack they are trying to perform.
These are just some types of security threats to give you a general idea of the number and types of methods intruders have at their disposal.
Other sites you may want to see:
Entertainment on Flixya: http://visalittleboy.flixya.com/
The Kingdom of Wonder: http://welcome2cambodia.blogspot.com/
Daily Blogging: http://visablogging.blogspot.com/
Love Sharing: http://visa-love.blogspot.com/
All about Love: http://visa-love.blogspot.com/
Learning English Online: http://visa-elb.blogspot.com/
Discovery Internet: http://visa-isp.blogspot.com/