2.2.4.7.2.2.2 Ensure 'Dif and Sylk files' is set to 'Enabled: Open/Save blocked, use open policy'

Information

This policy setting determines whether users can open, view, edit, or save Excel files with Dif and Sylk file format.

Open/Save blocked, use open policy: Both opening and saving of the file type will be blocked. The file will open based on the policy setting configured in the 'default file block behavior' key.

Note: Use Open Policy action is defined by the Set default file block behavior group policy setting which is included in this benchmark.

The recommended state for this setting is: Enabled: Open/Save blocked, use open policy.

Rationale:

DIF and SYLK are text-only file formats that are used to exchange data between different applications, such as Excel. If a vulnerability is discovered that affects these kinds of files, use this setting to protect the organization against attacks by temporarily preventing users from opening files in these formats until a security patch is available.

Using legacy file formats could allow malicious code to become active on a user's computer or the network.

Impact:

Users will not be able to open, save, or view Dif and Sylk files.

Solution

To establish the recommended configuration via GP, set the following UI path to Enabled: Open/Save blocked, use open policy.

User Configuration\Administrative Templates\Microsoft Excel 2016\Excel Options\Security\Trust Center\File Block Settings\Dif and Sylk Files

Default Value:

Disabled. (The file type will not be blocked.)

See Also

https://workbench.cisecurity.org/benchmarks/12129

Item Details

Category: SYSTEM AND INFORMATION INTEGRITY

References: 800-53|SI-3c.2.

Plugin: Windows

Control ID: e1cb849c0dafc6054f6ae9c9924f8340c798526dc7e7e831e1c4034349fe2a67