Adobe 22002486 Digital Signature User Guide - Page 132

External Content and Document Security - download

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External Content and Document Security Document access to internal and external content such as the Internet, attachments, and embedded multimedia represents a security risk. Users should configure their application so that it operates at an acceptable risk level. In enterprise settings, administrators should either preconfigure client installations or distribute instructions for setting up the application correctly. For details about application settings that control how documents interact with elements outside of the document, see the following:  "Enhanced Security" on page 132  "Controlling Multimedia" on page 136  "Setting JavaScript Options" on page 139  "Working with Attachments" on page 141  "Controlling Access to Referenced Files and XObjects" on page 145  "Internet URL Access" on page 146 9.1 Enhanced Security Like all other file formats, a PDF or an FDF file could contain a malicious script or perform some action that can damage a computer or steal data when it is run. Enhanced Security enables control of potentially risky behavior by allowing users to turn on enhanced security and either prevent dangerous actions altogether or else only permit them based on whether they reside in a privileged location. These behaviors include: silent printing; cross-domain access, external stream access, and internet access; and script and data injection. For example, if a PDF from your company has an embedded script, it downloads; otherwise, it is blocked. Acrobat and Reader provide two ways to block potentially unsafe PDFs:  A system administrator can add Internet domain names to the crossdomain.xml file on the server. Only files from locations listed in the crossdomain.xml file can be downloaded to individual computers.  Individuals can identify specific files, folders, or URLs (hosts) as privileged locations in the Enhanced Security Preferences dialog. Items in privileged locations bypass enhanced security restrictions. Any actions, such as loading data from the Internet or running a script are allowed. For example, Enhanced Security blocks FDFs from a loading data from unknown websites. If you add the FDF to your list of privileged locations, Acrobat allows the data to be loaded. At a high level, Enhanced Security includes the following:  Preventing silent printing; cross-domain access, external stream access, and internet access; and script and data injection.  Allowing dangerous behavior for only the specified privileged locations. These locations can be a file, directory, or host server.  FDF behavior is fundamentally altered when this feature is on. For details, see Distributing and Migrating Security Settings. 132

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132
External Content and Document Security
Document access to internal and external content such as the Internet, attachments, and embedded
multimedia represents a security risk. Users should configure their application so that it operates at an
acceptable risk level. In enterprise settings, administrators should either preconfigure client installations or
distribute instructions for setting up the application correctly.
For details about application settings that control how documents interact with elements outside of the
document, see the following:
“Enhanced Security” on page 132
“Controlling Multimedia” on page 136
“Setting JavaScript Options” on page 139
“Working with Attachments” on page 141
“Controlling Access to Referenced Files and XObjects” on page 145
“Internet URL Access” on page 146
9.1
Enhanced Security
Like all other file formats, a PDF or an FDF file could contain a malicious script or perform some action that
can damage a computer or steal data when it is run. Enhanced Security enables control of potentially risky
behavior by allowing users to turn on enhanced security and either prevent dangerous actions altogether
or else only permit them based on whether they reside in a privileged location. These behaviors include:
silent printing; cross-domain access, external stream access, and internet access; and script and data
injection. For example, if a PDF from your company has an embedded script, it downloads; otherwise, it is
blocked.
Acrobat and Reader provide two ways to block potentially unsafe PDFs:
A system administrator can add Internet domain names to the crossdomain.xml file on the server. Only
files from locations listed in the crossdomain.xml file can be downloaded to individual computers.
Individuals can identify specific files, folders, or URLs (hosts) as privileged locations in the Enhanced
Security Preferences dialog. Items in privileged locations bypass enhanced security restrictions. Any
actions, such as loading data from the Internet or running a script are allowed. For example, Enhanced
Security blocks FDFs from a loading data from unknown websites. If you add the FDF to your list of
privileged locations, Acrobat allows the data to be loaded.
At a high level, Enhanced Security includes the following:
Preventing silent printing; cross-domain access, external stream access, and internet access; and script
and data injection.
Allowing dangerous behavior for only the specified privileged locations. These locations can be a file,
directory, or host server.
FDF behavior is fundamentally altered when this feature is on. For details, see
Distributing and
Migrating Security Settings
.