STIGQter: STIG Summary: Microsoft Office 365 ProPlus Security Technical Implementation Guide Version: 2 Release: 2 Benchmark Date: 23 Apr 2021:

The warning about invalid digital signatures must be enabled to warn Outlook users.

DISA Rule

SV-223357r508019_rule

Vulnerability Number

V-223357

Group Title

SRG-APP-000207

Rule Version

O365-OU-000012

Severity

CAT II

CCI(s)

• CCI-001662 - The information system takes organization-defined corrective action when organization-defined unacceptable mobile code is identified.

Weight

10

Fix Recommendation

Set the policy value for User Configuration >> Administrative Templates >> Microsoft Outlook 2016 >> Security >> Cryptography >> Signature Warning to "Enabled" "Always warn about invalid signatures".

Check Contents

Verify the policy value for User Configuration >> Administrative Templates >> Microsoft Outlook 2016 >> Security >> Cryptography >> Signature Warning is set to "Enabled" "Always warn about invalid signatures".

Use the Windows Registry to navigate to the following key:

HKCU\software\policies\microsoft\office\16.0\outlook\security

If the value for warnaboutinvalid is set to REG_DWORD = 1, this is not a finding.

Vulnerability Number

V-223357

Documentable

False

Rule Version

O365-OU-000012

Severity Override Guidance

Verify the policy value for User Configuration >> Administrative Templates >> Microsoft Outlook 2016 >> Security >> Cryptography >> Signature Warning is set to "Enabled" "Always warn about invalid signatures".

Use the Windows Registry to navigate to the following key:

HKCU\software\policies\microsoft\office\16.0\outlook\security

If the value for warnaboutinvalid is set to REG_DWORD = 1, this is not a finding.

Check Content Reference

M

Target Key

4099

Comments