DTOO257 - S/Mime interoperability with external clients for message handling must be configured.

Information

In some situations, administrators might wish to use an external program, such as an add-in, to handle S/MIME message decryption. If your organization works with encrypted messages that the decryption functionality in Outlook cannot handle appropriately, this setting can be used to configure Outlook to hand S/MIME messages off to an external program for decryption. If no external program has been authorized however, misconfiguring this setting could allow unauthorized and potentially dangerous programs to handle encrypted messages, which could compromise security.

Solution

Set the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2013 -> Security -> Cryptography 'S/MIME interoperability with external clients' to 'Enabled (Handle internally)'.

See Also

https://iasecontent.disa.mil/stigs/zip/U_MS_Outlook_2013_V1R12_STIG.zip

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-8, CAT|II, CCI|CCI-000803, Rule-ID|SV-54003r1_rule, STIG-ID|DTOO257, Vuln-ID|V-17790

Plugin: Windows

Control ID: 3bdd938a958245a977f2eb808ab8cc4e2e88f4977b9483348ae369009fd2aaf1