Check: O365-OU-000002
Microsoft Office 365 ProPlus STIG:
O365-OU-000002
(in versions v2 r11 through v1 r2)
Title
Outlook must use remote procedure call (RPC) encryption to communicate with Microsoft Exchange servers. (Cat II impact)
Discussion
This policy setting controls whether Outlook uses remote procedure call (RPC) encryption to communicate with Microsoft Exchange servers. If you enable this policy setting, Outlook uses RPC encryption when communicating with an Exchange server. Note: RPC encryption only encrypts the data from the Outlook client computer to the Exchange server. It does not encrypt the messages themselves as they traverse the Internet. If you disable or do not configure this policy setting, RPC encryption is still used by default. This setting allows you to override the corresponding per-profile setting.
Check Content
Verify the policy value for User Configuration >> Administrative Templates >> Microsoft Outlook 2016 >> Account Settings >> Exchange >> Enable RPC encryption is set to "Enabled". Use the Windows Registry to navigate to the following key: HKCU\software\policies\microsoft\office\16.0\outlook\rpc If the value for enablerpcencryption is set to REG_DWORD = 1, this is not a finding.
Fix Text
Set the policy value for User Configuration >> Administrative Templates >> Microsoft Outlook 2016 >> Account Settings >> Exchange >> Enable RPC encryption to "Enabled".
Additional Identifiers
Rule ID: SV-223347r879892_rule
Vulnerability ID: V-223347
Group Title: SRG-APP-000575
Expert Comments
CCIs
Number | Definition |
---|---|
CCI-001967 |
The information system authenticates organization-defined devices and/or types of devices before establishing a local, remote, and/or network connection using bidirectional authentication that is cryptographically based. |
Controls
Number | Title |
---|---|
IA-3 (1) |
Cryptographic Bidirectional Authentication |