The A+ Exams Guide: (Exam 220-301), (Exam 220-302) (TestTakers Guides)

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Windows Me Networking and the Internet

Windows Me offers the Home Networking Wizard to set up local connections and the Internet Connection Wizard to help you establish a connection to the Internet. In previous versions of the Windows 9.x family, you had to manually configure your network card and install necessary protocols and clients through the Network applet in the Control Panel. This can all still be done the same way, but the Home Networking and Internet Connection Wizards will accomplish all of this for you, including setting up and installing necessary protocols for features like Internet Sharing. All of the protocols handled by Windows 9.x are supported in Windows Me (e.g., NetBEUI, TCP/IP, etc.) and are handled the same. For information on these protocols please refer to Chapter 11 on Windows 9.x.

First, we will take a look at the steps necessary to create an Internet connection in Windows Me.

Create an Internet Connection

Creating an Internet connection can be started in several ways. You can:

Essentially, what you have done by using the ICW (Internet Connection Wizard) is avoid having to set your TCP/IP and dial-up networking settings manually (and installed Dial-Up Networking, had it not been installed previously). Should you need to edit the settings or set up a new dial-up connection, you can do so from the Dial-Up Networking folder located at Start > Settings > Dial-Up Networking (which is possible if your ISP requires you to change settings due to connection failure).

Dial-Up Networking

Dial-up networking is handled exactly in the same way as it is for the rest of the Windows 9.x family. Again, it can be found at Start > Settings > Dial-Up Networking. From there, you will have access to any previous connections or the ability to create a new one. If you are modifying an existing connection, right-click on it from the Dial-Up Networking folder, and click Properties. Dial-up networking handles standard modem connections, ISDN connections, and null-modem connections between serial ports. From the General tab, you can choose from the following:

Creating a Peer-to-Peer Network

Creating a peer-to-peer Network in Windows Me is just as easy as setting up an Internet connection. To start, go to Start > Programs > Accessories > Communications > Home Networking Wizard. At the introductory screen, click Next.

Connecting to a Windows NT/2000 Server

You can still connect to a Windows 2000/NT server using the Home Networking Wizard. However, you must take the following into consideration:

Creating a FireWire Subnet

Users who have created an Ethernet or modem network and use a mobile device or laptop may want to consider setting up a subnet (or secondary network) using IEEE 1394 (FireWire) or wireless connection so that they can move about freely with the mobile device while having access to all resources. If you are using an external DSL or cable modem, you will require two Ethernet cards on your primary ICS (Internet Connection Sharing) machine where the Internet is shared from. Otherwise, you will need only one to connect to the rest of your network. Make sure that you have ICS set up on your primary ICS server before you begin. To create this subnet:

Cookies

A cookie is a message that is sent or ‘transmitted’ to a Web server from a Web browser. It is important to note that a cookie can also be referred to as a state object or persistent cookie. The cookie is used to provide the Web server with unique information that is used to identify where the request to the server is coming from. In other words, the cookie provides information about you. When you access pages on the Internet and enter your personal information into Web forms, that information along with other prepared information is combined into a file called a cookie. Most often, server-side scripts known as CGI (Common Gateway Interface) scripts are used to control what happens with the cookie. The next time you happen upon the same Web site, your Internet browser will automatically forward the locally stored cookie to that Web site’s server. If set up to do so, the server will provide you with a prepacked, customized page that targets you for specific advertisements. In other words, you will get ‘spammed.’

Many Web servers use trusted cookies as their only form of authentication. This widespread misuse of cookies has spawned a major security threat to both Web servers and users alike. If an attacker, or ‘cookie hijacker,’ is able to infiltrate a user’s session while the user is logged on to a server service, the attacker can steal the user’s cookie and use it to access such things as account information. A common practice that attackers use to grab cookies during an active session is to execute a fake JavaScript routine on an unprotected server.

Although many servers are open to this cookie authentication exploitation, most servers that provide important financial information and extremely sensitive data have more secure authentication mechanisms and devices in place.

There are several good ways to protect your system from the threats to security provided so nicely by the use of cookies. You can set up your Internet browser to alert you when a cookie is present, you can direct your browser to only download cookies from trusted sites, or you can disable cookies altogether. Depending on your operating system and Internet browser, this procedure will vary.

JavaScript

JavaScript is a programming script language that is supported by Internet browsers provided by Netscape and Microsoft. JavaScript is commonly used by Web developers to interact with Web pages, which are typically created using HTML or XML source codes. In simple terms, JavaScript allows developers to spruce up Web pages by adding features such as self-updating software packages, pop-up windows, link-to pages, and 3D interactive worlds to new or existing Internet Web pages. JavaScript is considered to be a portable, object-oriented, robust and secure scripting language.

The productive tools that we manufacture to design and create a better, more intuitive Internet experience all seem to come with a heavy price tag concerning security. Java, JavaScript, and Java applets (little programs sent with Web pages that do not require user interaction) are no exception. They all provide transportation mechanisms that can allow attackers to insert code to infiltrate and destroy your system. JavaScript, applets, and Java are programs that actually run on your system.

Hijackers and attackers often create scripts and applets, which are oftentimes able to circumvent network security parameters. They can be used to manipulate files on users’ computers.

Signed Applets

As mentioned earlier, applets are small programs that contain scripts that are sent with Web pages to users. Applets, such as Java applets, allow calculations, animations, and other functions to take place on a user’s system without a need for communication to take place with the applet-providing server.

Applets can contain malicious code that can easily destroy a system if allowed to run. A popular technique known as sandboxing is often used to quarantine applets that appear suspicious or malicious.

Signed applets are applets that contain a digital signature. They are a means of proving that an applet has come from a trusted location, author, or site. Signed applets receive permission to access local system resources. Plain applets only have access to the directories from which they originally run. Some books state that signed applets cannot be altered. This is simply not true. Anyone can create or forge a signed applet. This makes them very dangerous and provides a huge security vulnerability to local as well as networked systems.

Note 

It is important to note that most applets on the Web are unsigned applets. These applets can be assigned various security levels, which include untrusted, high, medium, and low levels of security. Please refer to Table 14.1 for the various levels of unsigned applet security.

Table 14.1: Applet Security Levels

Applet Security Level

Action Taken

Untrusted

Untrusted applets do not have permission to run on a system at all. They only have the ability to start.

High

Applets with this security rating run under what are considered safe restrains and are only permitted certain functions. They are not permitted to carry out unsafe actions. They cannot access most browser settings. They cannot read, write, delete, or change files. They can only listen to network ports located above port 1024. They cannot access a system’s printer queue or clipboard.

Medium

These applets can run under safe restraints. By default, if one of these applets attempts to read, write, change, or perform any of the other “High” restraints, you will prompted (warned) by your Internet browser. Next, you may grant the requested permission to the applet if you choose.

Low

This level carries the greatest security risk. Applets with Low security run under minimum restraint. Your browser will not warn you the actions listed above unless the applet attempts to start local applications.

ActiveX

ActiveX is a set of object-oriented programs, technologies, and tools that are Microsoft’s answer to Java technology, which by the way was created by Sun Microsystems. ActiveX is basically a combination, or ‘outgrowth’ of the Microsoft technologies known as OLE (Object Linking and Embedding) and COM (Component Object Model). When this technology is used in a networked environment that provides directory support and other service, the COM technology becomes DCOM (Distributed Component Object Model).

The goal of this technology is to create a self-sufficient program, known as a component or ActiveX control, which can be run anywhere your ActiveX network exists.

ActiveX’s controls, or ‘components,’ can be compared to Java applets, and can be reused by applications and other systems throughout your network.

ActiveX provides a power tool for developers and programmers. Unfortunately, ActiveX carries with it security risks, as JavaScript and applets do. But, the ActiveX security model is quite different from the security controls in place for Java and Java applets. As you may recall, Java applets are restricted based on a set of actions that are considered safe. The ActiveX security model does not limit an application package to a set of individual restrictive controls. Instead, its controls are based on digital signatures. These digital signatures are registered and certified with a trusted digital authority, such as VeriSign. When a person registers a software package or application with a trusted CA (Certificate Authority), they are agreeing that the package or ‘ActiveX Control’ is free of malicious code. From that point on, the risks involved with downloading the controls are totally the responsibility of the user.

In simple terms, the main weaknesses or problems associated with ActiveX controls are:

If you need help troubleshooting problems associated with active content such as JavaScript and ActiveX using Internet Explorer, Microsoft provides an excellent white paper on the subject. You will also be shown how to disable dangerous active content altogether in this white paper: http://support.microsoft.com/default.aspx?scid=KB;EN-US;Q154036

To access the ActiveX settings for Internet Explorer, navigate to Internet Explorer > Tools > Internet Options > Security Settings. Choose the network resource where you wish to edit ActiveX settings (e.g., Internet, Local Intranet, Trusted Sites, Restricted Sites), and Reset custom settings (see Figure 14.9). From here, you will be able to Disable/Enable/Prompt settings for:

CGI

The Common Gateway Interface is a language-independent interface or standard that Internet Web servers use to pass a user’s request to an application program and forward a response back to the Web server, which in turn provides the results to the user. In English, when a user fills out an HTML form on a Web page, a CGI program is typically used to process the form’s data behind the scenes and get the information back to the server. This allows Web servers to dynamically serve and interact with the users. The actual method of passing data between a server and an application is called the CGI.

CGI programs run on Web servers and are considered to be server-side applications. JavaScript, applets, and ActiveX controls are run on individual systems and are considered client-side programs. A disadvantage with using CGI programs is that they start a new service on a Web server every time a CGI program runs. This can result in a major decrease in the performance of a Web server.

The use of CGI programs allows the vulnerabilities associated with HTTP to be exploited. Also, in order for CGI programs to work, they are written to run on most operating systems and have access to important server system files, as well as connected hosts.

Poorly executed CGI scripts and lack of or improper file system permissions can open the security hole doors and leave your system vulnerable to attack.


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