Blackberry JAVA DEVELOPMENT ENVIRONMENT - - FUNDAMENTALS GUIDE Especificaciones descargar pdf (Pagina 16)

Attack Surface Analysis of BlackBerry Devices

BlackBerry Persistence Model

• Proprietary

• Application needs to be signed

• Can store any object that implements the

Persistable interface (plus some native types).

• Data can be shared between applications subject to signing and other access controls. For informa-

tion on how to protect data from inappropriate use, see the

ControlledAccess class in the RIM Device

Java Library

and the BlackBerry JDE Development Guide.

J2ME File System

Newer BlackBerry models (including the Pearl 8100) have traditional file system support, facilitated by the

javax.microedition.io.file package. Applications can enumerate files and directories on the file system,

as well as create, edit, and delete files and directories. Unsigned applications will cause the user to be

prompted to allow access to the file system (Figure 8). The file system can have multiple roots. For exam-

ple, one root for the onboard phone storage, and one for an inserted memory card. Files are addressed using

a URL format. For example:

file:///SDCard/blackberry/pictures/neo.jpg

While .jar or .cod files residing on the J2ME file system can be modified

by an application, no typical user scenario exists where a user will then

subsequently install that .jar or .cod file from the phone or removable

memory card. The existing applications installed on the BlackBerry are

not visible at all to this file system and cannot be modified by it. Also

note that many BlackBerry applications are signed, and modification of

such a signed .cod file will invalidate its signature. Therefore traditional

file infector viruses are not feasible for the BlackBerry, short of the dis-

covery of a new vulnerability. Symantec are not aware of any such vulner-

ability at the time of writing.

USB Mass Storage

When the BlackBerry is plugged into a PC via the USB cable, the user is

given the option of mounting the device as a USB mass storage drive.

Note that the media card must be inserted in order for Mass Storage

mode to be enabled, and only the file system of the media card is accessible in any case. If this option is

selected, the BlackBerry media card file system appears as another drive on the host PC. Users and appli-

cations on the PC can then freely copy files to and from the BlackBerry as easily as any storage drive.

This could result in the BlackBerry accidentally or maliciously being used as a conveyance of malware. For

example threats such as W32.Fujacks.AW

copy themselves to removable drives automatically. Although

Figure 8: Unsigned application access to

the file system

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Blackberry JAVA DEVELOPMENT ENVIRONMENT - - FUNDAMENTALS GUIDE Especificaciones Pagina 16