¶ … Security
Mobile Code
Mobile code creates a required programming device to provide adaptability to form distributed systems for the Internet viz. Java Applets. (Mobile Code Security) Mobile code may be defined as small bits of software, which can without a user initiating action or even without his knowledge, be automatically downloaded into the workstation and executed. Without suitable controls appropriately positioned, there is the possibility of security risks, as these executable programs are downloaded from a server. Though mobile code meets the demand for functionality, it is necessary to protect any organization's system and networks from malicious mobile code, by writing a suitable security policy. (Writing Mobile Code Policies) Every initiator has the capability to generate independent mobile agents that can remit to unrestricted number of hosts and thereafter come back to the initiator. (Mobile Code Security)
A user was to be allowed to download a small piece of software, which enabled the user to increase their online experience. In the beginning this software could be used by Program Developers for several functions, without putting a load on the server. These functions include customising pages, doing data validation on forms, and doing some basic processing. The release of Java language and Java Virtual Machine environment by Sun created unlimited possibilities and was expected to change the whole picture of the Internet. It now became possible for a Programmer to create a single program and run it anywhere where Java Virtual Machine environment was available. The availibility of Java Virtual Machine in most browsers led to the birth of the mobile code.(Writing Mobile Code Policies)
Types of Mobile Code:
Let us examine some of the frequently and commonly seen forms of mobile code. The Internet Explorer has Embedded Script -JScript / VBScript, embedded within web pages and forms the first set of common forms of mobile code. These scripts enable the objects on a web page to be manipulated. These languages also enable the loading of objects like ActiveX controls and Java applets. The Windows Script Host allows the running of VBScript and JScript on any Windows platform. They run in the user's security context, as they are not under restrictions that are placed on code run in the browser. So if downloaded it allows the user any action including the manipulation of registry and file system by using objects present or calling upon other installed applications with the help of Component Object Model COM interfaces. COM forms the architecture of Microsoft to make programming objects that van be used again and again and give services to other programs. (Managing Mobile Code with Microsoft Technologies)
An ActiveX control is nothing but a COM and is another common form of mobile code. The ActiveX control has been designed so that it can be downloaded and made use of in web pages. On installing it, it runs in the security context of the web browser and is capable of doing any operation a user can. So ActiveX controls are a powerful tool for browser-based applications. Yet, it can pose a security check if normal safeguards are not taken. Similar to ActiveX controls are Java Applets and another common form of mobile code. Java applets consist of reusable code modules. They can be downloaded and installed on any client machine. The downloaded applet gets loaded into the Java Virtual Machine that controls the running of the applet. So the control restricts the functionality imposed by the Java Virtual Machine. Yet it offers better security by this. "Built-in" Objects is yet another form of mobile code and Internet Explorer uses these objects to perform scripting functions. They can be accessed from VBScriptor JScript. (Managing Mobile Code with Microsoft Technologies)
Quite a few of the Microsoft and other applications permit the Visual Basic Applications to be manipulated within other applications. Visual Basic Applications allows similar types of services as VBScript, being another form of it. These scripts get embedded within application documents and can be activated by the opening of certain application actions, like a document being opened. (Managing Mobile Code with Microsoft Technologies) Mobile code applications, like Java applets, ActiveX controls, JavaScript, and other auto-executable applications, are powerful applications in the distribution of information. The increasing power also creates an increased potential for unscrupulous individuals to exploit these applications for towards their goals. (Mobile code applications are the latest online-security threat)
Security Considerations With Respect to allowing Mobile Code into internal network:
Network oriented technologies possess extensively diverse security models and has varied ranges and advantages while...
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