7.5 Ensure TLS 1.1 is Disabled

Information

The TLS 1.1 protocol is not considered cryptographically secure, therefore should be disabled.

Rationale:

Disabling weak protocols will help ensure the confidentiality and integrity of in-transit data.

Impact:

TLS 1.1 may be needed for backward compatibility.

Warning: Fully test the application to ensure that backwards compatibility is not needed. If it is, build in exceptions as necessary for backwards compatibility.

Solution

Perform the following to disable TLS 1.1:

Set the following Registry key to 0.

HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.1\Server:Enabled
HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.1\Client:Enabled

Set the following Registry key to 1.

HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.1\Server:DisabledByDefault
HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.1\Client:DisabledByDefault

To disable using PowerShell enter the following command:

New-Item 'HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.1\Server' -Force | Out-Null

New-Item 'HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.1\Client' -Force | Out-Null

New-ItemProperty -path 'HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.1\Server' -name 'Enabled' -value '0' -PropertyType 'DWord' -Force | Out-Null

New-ItemProperty -path 'HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.1\Client' -name 'Enabled' -value '0' -PropertyType 'DWord' -Force | Out-Null

New-ItemProperty -path 'HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.1\Server' -name 'DisabledByDefault' -value '1' -PropertyType 'DWord' -Force | Out-Null

New-ItemProperty -path 'HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.1\Client' -name 'DisabledByDefault' -value '1' -PropertyType 'DWord' -Force | Out-Null

See Also

https://workbench.cisecurity.org/benchmarks/13949

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-7(8), CSCv7|14.4

Plugin: Windows

Control ID: cafe75377b2dfb380d2c9156cb3855cb87b95bac162d33a99d1d6d30b0c5bf90