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

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-223345	O365-LY-000002	SV-223345r1043178_rule	CCI-001184	medium
Description
Prevents from HTTP being used for SIP connection in case TLS or TCP fail.
STIG			Date
Microsoft Office 365 ProPlus Security Technical Implementation Guide			2025-03-05

Related Frameworks

1 mapping across 4 frameworks

SCF0 mappings

No source states a mapping between these directly.

Also reachable in 3 hops (1) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

NET-09Session Integrity

1.00

DISA STIG Benchmark (XCCDF)3intersects(normalised)
DISA CCI List2025-01-23equal to(normalised)
SCF Secure Traceability Relationship Mapping (STRM)2026.2equal to

NIST 800-530 mappings

No source states a mapping between these directly.

Also reachable in 2 hops (30) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

AC-17(2)Protection of Confidentiality and Integrity Using Encryption

1.00

DISA STIG Benchmark (XCCDF)3intersects(normalised)
DISA STIG Benchmark (XCCDF)V1R1our copyintersects(normalised)
DISA STIG Benchmark (XCCDF)V1R1intersects(normalised)
DISA CCI List2025-01-23equal to(normalised)

AU-10(1)Association of Identities

1.00

DISA STIG Benchmark (XCCDF)3intersects(normalised)
DISA STIG Benchmark (XCCDF)2our copyintersects(normalised)
DISA STIG Benchmark (XCCDF)2intersects(normalised)
DISA CCI List2025-01-23equal to(normalised)

AU-10(2)Validate Binding of Information Producer Identity

1.00

DISA STIG Benchmark (XCCDF)3intersects(normalised)
DISA STIG Benchmark (XCCDF)2our copyintersects(normalised)
DISA STIG Benchmark (XCCDF)2intersects(normalised)
DISA CCI List2025-01-23equal to(normalised)

AU-9(3)Cryptographic Protection

1.00

DISA STIG Benchmark (XCCDF)3intersects(normalised)
DISA STIG Benchmark (XCCDF)2our copyintersects(normalised)DISA STIG Benchmark (XCCDF)V2R6our copyintersects(normalised)
DISA STIG Benchmark (XCCDF)2intersects(normalised)DISA STIG Benchmark (XCCDF)V2R6intersects(normalised)
DISA CCI List2025-01-23equal to(normalised)

CM-14Signed Components

1.00

DISA STIG Benchmark (XCCDF)3intersects(normalised)
DISA STIG Benchmark (XCCDF)V2R2our copyintersects(normalised)
DISA STIG Benchmark (XCCDF)V2R2intersects(normalised)
DISA CCI List2025-01-23equal to(normalised)

CM-5(3)Signed Components

1.00

DISA STIG Benchmark (XCCDF)3intersects(normalised)
DISA STIG Benchmark (XCCDF)V2R2our copyintersects(normalised)
DISA STIG Benchmark (XCCDF)V2R2intersects(normalised)
DISA CCI List2025-01-23equal to(normalised)

CM-6Configuration Settings

1.00

DISA STIG Benchmark (XCCDF)3intersects(normalised)
DISA STIG Benchmark (XCCDF)V1R2our copyintersects(normalised)
DISA STIG Benchmark (XCCDF)V1R2intersects(normalised)
DISA CCI List2025-01-23equal to(normalised)

CM-7Least Functionality

1.00

DISA STIG Benchmark (XCCDF)3intersects(normalised)
DISA STIG Benchmark (XCCDF)V1R1our copyintersects(normalised)
DISA STIG Benchmark (XCCDF)V1R1intersects(normalised)
DISA CCI List2025-01-23equal to(normalised)

IA-2(1)Multi-factor Authentication to Privileged Accounts

1.00

DISA STIG Benchmark (XCCDF)3intersects(normalised)
DISA STIG Benchmark (XCCDF)1our copyintersects(normalised)
DISA STIG Benchmark (XCCDF)1intersects(normalised)
DISA CCI List2025-01-23equal to(normalised)

IA-2(12)Acceptance of PIV Credentials

1.00

DISA STIG Benchmark (XCCDF)3intersects(normalised)
DISA STIG Benchmark (XCCDF)1our copyintersects(normalised)
DISA STIG Benchmark (XCCDF)1intersects(normalised)
DISA CCI List2025-01-23equal to(normalised)

+20 more (top 10 by confidence shown)

NIST 800-1710 mappings

No source states a mapping between these directly.

Also reachable in 3 hops (1) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

3.13.15

1.00

DISA STIG Benchmark (XCCDF)3intersects(normalised)
DISA CCI List2025-01-23equal to(normalised)
NIST SP 800-171 Rev 2, Appendix DRev 2 (Feb 2020, errata Jan 2021)equal to(normalised)

CCI1 mapping

CCI-001184

1.00

DISA STIG Benchmark (XCCDF)3intersects(normalised)

Details

Check Text (C-223345r1043178_chk)

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 (F-25006r442255_fix)

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".