Prompting behavior for Level 1 attachments on sending must be configured.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-17602	DTOO242 - Outlook	SV-33582r1_rule	ECSC-1	Medium

Description
To protect users from viruses and other harmful files, Outlook uses two levels of security, designated Level 1 and Level 2, to restrict access to files attached to e-mail messages or other items. Outlook completely blocks access to Level 1 files by default, and requires users to save Level 2 files to disk before opening them. Potentially harmful files can be classified into these two levels by file type extension, with all other file types considered safe. By default, when users attempt to send an item to which a level 1 file has been attached, Outlook warns them that the message contains a potentially unsafe attachment and that the recipient might not be able to access it. If this configuration is changed, Outlook will not display the warning when users send such items, which can cause users to lose access to important data.

Description

To protect users from viruses and other harmful files, Outlook uses two levels of security, designated Level 1 and Level 2, to restrict access to files attached to e-mail messages or other items. Outlook completely blocks access to Level 1 files by default, and requires users to save Level 2 files to disk before opening them. Potentially harmful files can be classified into these two levels by file type extension, with all other file types considered safe. By default, when users attempt to send an item to which a level 1 file has been attached, Outlook warns them that the message contains a potentially unsafe attachment and that the recipient might not be able to access it. If this configuration is changed, Outlook will not display the warning when users send such items, which can cause users to lose access to important data.

STIG	Date
Microsoft Outlook 2010	2014-01-07

Details

Check Text ( C-34043r1_chk )
The policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2010 -> Security -> Security Form Settings -> Attachment Security “Do not prompt about Level 1 attachments when sending an item” must be set to “Disabled”. Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\14.0\outlook\security Criteria: If the value DontPromptLevel1AttachSend is REG_DWORD = 0, this is not a finding.

Check Text ( C-34043r1_chk )

The policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2010 -> Security -> Security Form Settings -> Attachment Security “Do not prompt about Level 1 attachments when sending an item” must be set to “Disabled”.

Procedure: Use the Windows Registry Editor to navigate to the following key:

HKCU\Software\Policies\Microsoft\Office\14.0\outlook\security

Criteria: If the value DontPromptLevel1AttachSend is REG_DWORD = 0, this is not a finding.

Fix Text (F-29726r1_fix)
Set the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2010 -> Security -> Security Form Settings -> Attachment Security “Do not prompt about Level 1 attachments when sending an item” to “Disabled”.