SV-250540r1117186: Turn off Encryption Support must be enabled. | Microsoft Internet Explorer 11 STIG SCAP Benchmark

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Assessment Title

Rule Text

Turn off Encryption Support must be enabled.

Description

Discussion Text

This parameter ensures only DOD-approved ciphers and algorithms are enabled for use by the web browser by allowing the user to turn on/off support for TLS and SSL. TLS is a protocol for protecting communications between the browser and the target server. When the browser attempts to set up a protected communication with the target server, the browser and server negotiate which protocol and version to use. The browser and server attempt to match each other's list of supported protocols and versions and pick the most preferred match. Satisfies: SRG-APP-000514, SRG-APP-000555, SRG-APP-000625, SRG-APP-000630, SRG-APP-000635

How this relates to the STIG checklist: STIG vs SCAP benchmark.

IA Controls

NIST SP 800-53

Not mappedCCI-002450SV-59337V-46473

References

DPMS Target Microsoft Internet Explorer 11 DISA DPMS Target Microsoft Internet Explorer 11 4095

SCC Automation Reference

The reconstructed evaluation script behind this rule's OVAL check(s) — every module a compound check combines, with this rule's own concrete values and DISA's SCC tool's real per-module mechanism curated from static teardown of SCC releases.

# Windows PowerShell
# Reconstructed from oval:mil.disa.fso.ie:def:580
# Turn off Encryption Support must be enabled.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# 'turn off encryption support' setting is handled by Group Policy.
# registry_object (registry_test)
function test_1 {
  return ($null -ne (Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings' -Name 'SecureProtocols'))
}
# TLS 1.2 must be selected for the IE option 'turn off encryption support' via Group Policy.
# registry_object (registry_test)
function test_2 {
  return (((@{String='reg_sz';ExpandString='reg_expand_sz';Binary='reg_binary';DWord='reg_dword';MultiString='reg_multi_sz';QWord='reg_qword';None='reg_none'}[(Get-Item -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings').GetValueKind('SecureProtocols').ToString()]) -eq 'reg_dword') -and (((Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings' -Name 'SecureProtocols' -ErrorAction SilentlyContinue) | Select-Object -ExpandProperty 'SecureProtocols') -eq 2048))
}

if ((test_1 -and test_2)) {
  Write-Output "PASS"
} else {
  Write-Output "FAIL"
}

SCC Assessment

The automated check DISA's SCAP Compliance Checker runs to assess this control. Pick a release below to see exactly what it evaluates on the target system.

SCC version

Not available for this version yet.

Assessment Script Powered by AISyntax-verified

A standalone PowerShell script to assess this control automatically. Review before running it in your environment.

Syntax-checked as valid PowerShell. Not executed here — running it for real needs the actual ms_ie11 target this check assesses.

# OVAL Definition: oval:mil.disa.fso.ie:def:580
$regPath = "HKLM:\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings\SecureProtocols"
if (Test-Path $regPath) {
    $regData = Get-ItemProperty -Path $regPath
    if ($regData.Length -gt 0) {
        $tlsSetting = $regData.psobject.Properties | Where-Object { $_.Name -eq "EncryptionSupport" }
        if ($tlsSetting -and $tlsSetting.Value -eq 2048) {
            Write-Output "PASS"
            Exit 0
        }
    }
}
Write-Output "FAIL"
Exit 1

Remediation

Set the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Internet Explorer >> Internet Control Panel >> Advanced Page >> "Turn off Encryption Support" to "Enabled".

Select only "Only use TLS 1.2" from the drop-down box.