Title

An IIS 8.5 web server must maintain the confidentiality of controlled information during transmission through the use of an approved TLS version. (Cat I impact)

Discussion

Transport Layer Security (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.

Check Content

Access the IIS 8.5 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 2.0\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.

Fix Text

Access the IIS 8.5 Web Server. Navigate to: HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Server Create a REG_DWORD named "DisabledByDefault" with a value of "0". Create a REG_DWORD named "Enabled" with a value of "1". 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 2.0\Server HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\SSL 3.0\Server For each protocol: Create a REG_DWORD named "DisabledByDefault" with a value of "1". Create a REG_DWORD named "Enabled" with a value of "0".

Additional Identifiers

Rule ID: SV-214436r903078_rule

Vulnerability ID: V-214436

Group Title: SRG-APP-000439-WSR-000156

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.