TMA-CHROME-1.17

Ensure 'Enable online OCSP/CRL checks' is set to 'Disabled'

HighLevel 1Automatedchrome

Description

Google Chrome can reactivate soft-fail, online revocation checks although they can provide some benefit in most cases. If this setting is disabled, unsecure online OCSP/CRL checks are no longer performed. The recommended state for this setting is: Disabled (0) Rationale: CRLSets are primarily a means by which Chrome can quickly block certificates in emergency situations. As a secondary function they can also contain some number of non-emergency revocations. These latter revocations are obtained by crawling CRLs published by CAs. Online (i.e. 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:EnableOnlineRevocationChecks (REG_DWORD); compliant when it is 0. Remediation writes 0 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

$v = (Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome' -Name 'EnableOnlineRevocationChecks' -ErrorAction SilentlyContinue).'EnableOnlineRevocationChecks'; if ($null -eq $v) { 'unset' } elseif (($null -ne $v -and @(0) -contains [int64]$v)) { '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 'EnableOnlineRevocationChecks' -Value 0 -PropertyType DWord -Force | Out-Null

Properties

Operating systems: Any
Tags: chromebrowsercis-l1
Reference: CIS Google Chrome Benchmark v3.0.0 - 1.17 Ensure 'Enable online OCSP/CRL checks' is set to 'Disabled'

Check this host

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

shell

tmaegis scan --target chrome