Flash CS3 Documentation

Learning ActionScript 2.0 in Adobe Flash > Understanding Security > About local file security and Flash Player > Understanding local security sandboxes

Understanding local security sandboxes

There are several different security sandboxes in the Flash Player. Each one determines how a SWF file can interact with the local file system, the network, or both the local file system and network at the same time. Restricting how a file can interact with the local file system, or the network helps keep your computer and files safe. Understanding security sandboxes helps you develop and test Flash applications on your computer without encountering unexpected errors.

Local-with-file-system

For security purposes, Flash Player places all local SWF files, including all legacy local SWF files, in the local-with-file-system sandbox, by default (unless some other setting is made). For some legacy SWF files (Flash Player 7 and earlier), operations could be affected by enforcing restrictions on their access (no outside network access), but this provides the most secure default for the users' protection.

From this sandbox, SWF files may read from files on local file systems or UNC network paths (by using the XML.load() method, for example), but they may not communicate with the network in any way. This assures the user that local data cannot be leaked out to the network or otherwise inappropriately shared.

Local-with-networking

When local SWF files are assigned to the local-with-networking sandbox, they forfeit their local file system access. In return, the SWF files are allowed to access the network. However, a local-with-networking SWF file still is not allowed to read any network-derived data unless permissions are present for that action. Therefore, a local-with-networking SWF file has no local access, yet it has the ability to transmit data over the network and can read network data from those sites that designate site-specific access permissions.

Local-trusted

SWF files assigned to the local-trusted sandbox can interact with any other SWF files, and load data from anywhere (remote or local).

Flash CS3