Ensure 'Configure extension installation blocklist' is set to 'Enabled: *'

HighLevel 1Automatedchrome

Description

Enabling this setting allows you to specify which extensions the users can NOT install. Extensions already installed will be removed if blocklisted. Disabled (0): then the user can install any extension in Google Chrome. Rationale: This can be used to block extensions that could potentially allow remote control of the system through the browser. If there are extensions needed for securing the browser or for enterprise use, these can be enabled by configuring either the setting Configure extension installation allowlist or the... List policy: numbered REG_SZ values under HKLM\SOFTWARE\Policies\Google\Chrome\ExtensionInstallBlocklist. Compliant when one entry equals '*'; 'unset' when the list is empty.

How it is checked

Audit method: Windows registry

registry

$l = @((Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome\ExtensionInstallBlocklist' -ErrorAction SilentlyContinue).PSObject.Properties | Where-Object { $_.Name -notlike 'PS*' } | ForEach-Object { "$($_.Value)" }); if ($l.Count -eq 0) { 'unset' } elseif ($l -contains '*') { 'compliant' } else { 'non-compliant: ' + ($l -join ', ') }

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

Configure through Group Policy: Computer Configuration\Polices\Administrative Templates\Google\Google Chrome\Extensions\Configure extension installation blocklist = Enabled and a value of * for Extension IDs the user should be prevented from installing. Populate ExtensionInstallAllowlist with approved extension IDs before blocking '*'.

Properties

Operating systems: Any
Tags: chromebrowsercis-l1
Reference: CIS Google Chrome Benchmark v3.0.0 - 2.3.3 Ensure 'Configure extension installation blocklist' is set to 'Enabled: *'

Check this host

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

shell

tmaegis scan --target chrome