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V-223345

CAT II (Medium)

The HTTP fallback for SIP connection in Lync must be disabled.

Rule ID

SV-223345r1043178_rule

STIG

Microsoft Office 365 ProPlus Security Technical Implementation Guide

Version

V3R5

CCIs

CCI-001184

Discussion

Prevents from HTTP being used for SIP connection in case TLS or TCP fail.

Check Content

Verify the policy value for Computer Configuration >> Administrative Templates >> Skype for Business 2016 >> Microsoft Lync Feature Policies "Disable HTTP fallback for SIP connection" is set to "Enabled".

Use the Windows Registry Editor to navigate to the following key: 

HKLM\Software\Policies\Microsoft\office\16.0\lync

If the value disablehttpconnect is REG_DWORD = 1, this is not a finding.

Fix Text

Set the policy value for Computer Configuration >> Administrative Templates >> Skype for Business 2016 >> Microsoft Lync Feature Policies "Disable HTTP fallback for SIP connection" to "Enabled".