Ensure 'Controls the mode of DNS-over-HTTPS' is set to 'Enabled: DNS-over-HTTPS without insecure fallback'

MediumLevel 2Automatedchrome

Description

This controls the mode of the DNS-over-HTTPS resolver. Please note that this setting will only set the default mode for each query. The mode may be overridden for special types of queries, such as requests to resolve a DNS-over-HTTPS server hostname. Rationale: DNS over HTTPS (DOH) has a couple primary benefits: 1. Encrypting DNS name resolution traffic helps to hide your online activities, since DoH hides the name resolution requests from the ISP and from anyone listening on intermediary networks. 2. Audit reads the Group Policy registry value and prints 'compliant', 'unset' (policy not configured, reported as FAIL) or the non-compliant value. Registry value: HKLM\SOFTWARE\Policies\Google\Chrome:DnsOverHttpsMode (REG_SZ); compliant when it is 'secure' (whitespace-insensitive). Remediation writes secure locally; in a domain set it through the ADMX so Group Policy does not revert it.

How it is checked

Audit method: Windows registry

registry

$v = (Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome' -Name 'DnsOverHttpsMode' -ErrorAction SilentlyContinue).'DnsOverHttpsMode'; if ($null -eq $v) { 'unset' } elseif (($null -ne $v -and ("$v" -replace '\s','') -eq 'secure')) { 'compliant' } else { "non-compliant: $v" }

Expected output: compliant

How it is fixed

Fix method: Shell command

shell

$p = 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome'; if (-not (Test-Path -Path $p)) { New-Item -Path $p -Force | Out-Null }; New-ItemProperty -Path $p -Name 'DnsOverHttpsMode' -Value 'secure' -PropertyType String -Force | Out-Null

Properties

Operating systems: Any
Tags: chromebrowsercis-l2
Reference: CIS Google Chrome Benchmark v3.0.0 - 4.7 Ensure 'Controls the mode of DNS-over-HTTPS' is set to 'Enabled: DNS-over-HTTPS without insecure fallback'

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

shell

tmaegis scan --target chrome --level 2