V-218821

Discussion

TLS encryption is a required security setting for a private web server. Encryption of private information is essential to ensuring data confidentiality. If private information is not encrypted, it can be intercepted and easily read by an unauthorized party. A private web server must use a FIPS 140-2-approved TLS version, and all non-FIPS-approved SSL versions must be disabled. NIST SP 800-52 specifies the preferred configurations for government systems.

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Access the IIS 10.0 Web Server.

Navigate to:
HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Server

Verify a REG_DWORD value of "0" for "DisabledByDefault".
Verify a REG_DWORD value of "1" for "Enabled".

Navigate to:
HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.0\Server
HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.1\Server
HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\SSL 3.0\Server

Verify a REG_DWORD value of "1" for "DisabledByDefault".
Verify a REG_DWORD value of "0" for "Enabled".

If any of the respective registry paths do not exist or are configured with the wrong value, this is a finding.

SSL 3.0 is disabled by default in newer Operating Systems. If SSL 3.0 has a registry DWORD enabled with a value of 1, this is a finding. If this key is not present, this is not a finding.