Open/Save actions for Dif and Sylk files must be blocked.
An XCCDF Rule
Description
<VulnDiscussion>This setting specifies whether users can open, view, edit, or save files saved in the specified format. Enabling block of the specified format mitigates zero-day security attacks (which are attacks that occur between the time that a vulnerability becomes publicly known and a software update or service pack is available) by temporarily preventing users from opening specific types of files and to prevent a user from opening files that have been saved in earlier and pre-release (beta) Microsoft Office formats.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility>System Administrator</Responsibility><Responsibility>Information Assurance Officer</Responsibility><IAControls></IAControls>
- ID
- SV-53620r1_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
Set the policy value for User Configuration -> Administrative Templates -> Microsoft Excel 2013 -> Excel Options -> Security -> Trust Center -> File Block Settings "Dif and Sylk files" to "Enabled: Open/Save blocked, use open policy".