Title

Allow Users to demote an EMail Level 1 attachment to Level 2. (Cat II impact)

Discussion

Outlook 2007 uses two levels of security to restrict access to files attached to e-mail messages or other items. Files with specific extensions can be categorized as Level 1 (users cannot view the file) or Level 2 (users can open the file after saving it to disk). Users can freely open files of types that are not categorized as Level 1 or Level 2. By default, Outlook does not allow users to demote file types from Level 1 to Level 2. If this setting is Enabled, users can create a list of Level 1 file types to demote to Level 2 by adding the file types to the following registry key: HKEY_CURRENT_USER\Software\Microsoft\Office\Outlook\12.0\Security\Level1Remove If users can demote Level 1 files to Level 2, they will be able to access potentially dangerous files after saving them to disk, which could allow malicious code to affect their computers or compromise the security of sensitive information.

Check Content

The policy value for User Configuration -> Administrative Templates -> Microsoft Office Outlook 2007 -> Security -> Security Form Settings -> Attachment Security “Allow users to demote attachments to Level 2” will be set to “Disabled”. Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\12.0\Outlook\Security Criteria: If the value AllowUsersToLowerAttachments is REG_DWORD = 0, this is not a finding.

Fix Text

The policy value for User Configuration -> Administrative Templates -> Microsoft Office Outlook 2007 -> Security -> Security Form Settings -> Attachment Security “Allow users to demote attachments to Level 2” will be set to “Disabled”.

Additional Identifiers

Rule ID: SV-18677r1_rule

Vulnerability ID: V-17569

Group Title:

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.