Network System Security

Cross-Site Scripting (XSS) Cross-Site Scripting is a computer security vulnerability that is mostly found in web applications. XSS allows attackers to inject client-side scripts into web pages that are then viewed by others. The people that view this web page can then be infected without even knowing as the page appears to be normal. Depending on what scripts the attacker uses the effects can range from something very minor to a major security risk. XSS can be used to gain control and bypass the authorisation process. SQL Injection SQL Injection is a  technique  used to attack data driven applications and is implemented by adding parts of SQL statements in to entry fields within a website.This is done  in an attempt to get the website to accept a newly formed rouge SQL command to the database. SQL injection is a code injection  technique  that exploits a security vulnerability in an applications software. The vulnerability occurs when the user input field is incorrectly filtered.

Firewalls Firewalls are designed to prevent unauthorised access to a computer or network. You can implement a firewall in both hardware and software, or a combination of both. A firewall will monitor data packets coming in and out of the network it is protecting and will enforce the company's network security policy. It filters out the packets that look suspicious and do not meet the specified security criteria. Most organisations use firewalls to protect their network from the Internet. There are a few different types of firewall, these are: Packet Filtering Firewall Stateful Inspection Packet Filtering Firewall Proxy Firewall Packet Firewalls Packet filtering was the first type of firewall to be created, a packet filtering firewall will control what data can flow into and out of a network. It will accept or reject packets of data based on a set of user-defined rules, these rules are called ACLs. ACLs are lines of text that the firewall will apply to each packet of d

Emails are a very good method of communication; they do however have the potential to be harmful to a network.  Spam Guard Spam is one of the most common email security risks. Spam involves identical emails being sent to hundreds of thousands of people in the hope that a small percentage of the recipients will open them and be interested in them. The majority of spam emails are sent to advertise a product or service; however some of these emails may contain viruses or links to phishing websites. Roughly 130 billion spam emails are sent every day, this is why it is vital that you protect your organisation against it. In addition to wasting people’s time with unwanted email, spam also uses up a lot of network bandwidth slowing the whole network down. Spammers collect email addresses from chat rooms, websites, customer lists, newsgroups, and viruses which harvest users' address books, and are sold to other spammers. Sending the emails costs the spammer nothing, so even if only on