O365-CO-000019 - The MIME Sniffing safety feature must be enabled in all Office programs.

Information

Encryption is only as good as the encryption modules utilized. Unapproved cryptographic module algorithms cannot be verified and cannot be relied upon to provide confidentiality or integrity, and DoD data may be compromised due to weak algorithms. The use of TLS provides confidentiality of data in transit between the application server and client. FIPS 140-2 approved TLS versions include TLS V1.0 or greater.

TLS must be enabled and non-FIPS-approved SSL versions must be disabled. NIST SP 800-52 specifies the preferred configurations for government systems.

Solution

Set the policy value for Computer Configuration >> Administrative Templates >> Microsoft Office 2016 (Machine) >> Security Settings >> IE Security >> Mime Sniffing Safety Feature to 'Enabled' for all installed Office programs.

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_MS_Office_365_ProPlus_V3R1_STIG.zip

Item Details

Category: IDENTIFICATION AND AUTHENTICATION

References: 800-53|IA-7, CAT|II, CCI|CCI-000803, Rule-ID|SV-223301r961050_rule, STIG-ID|O365-CO-000019, STIG-Legacy|SV-108781, STIG-Legacy|V-99677, Vuln-ID|V-223301

Plugin: Windows

Control ID: 3ba0e19b5fc5560621da60453da17cca3e44976a4b690212b9d7f62b6df3625f