DTOO264 - Outlook - All signed messages as clear signed messages must be configured.

Information

When users sign e-mail messages with their digital signature and send them, Outlook uses the signature's private key to encrypt the digital signature but sends the messages as clear text, unless they are encrypted separately. If users change this functionality by clearing the Send clear text signed message when sending signed messages option in the E-mail Security section of the Trust Center, any recipients who are unable to access or use the sender's digital certificate will not be able to read the e-mail messages.

Solution

Set the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2010 -> Security -> Cryptography 'Send all signed messages as clear signed messages' to 'Enabled'.

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_MS_Outlook_2010_V1R13_STIG.zip

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6b., CAT|II, CCI|CCI-000366, Rule-ID|SV-33570r1_rule, STIG-ID|DTOO264, Vuln-ID|V-17800

Plugin: Windows

Control ID: e777b0858404c0a80924123b987683abcd7dd0fcbc26190a8d95344a2387165f