SV-221563r1015468: Extensions that are approved for use must be allowlisted. | Google Chrome Current Windows STIG SCAP Benchmark

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Assessment Title

Rule Text

Extensions that are approved for use must be allowlisted.

Description

Discussion Text

The allowlist should only contain organizationally approved extensions. This is to prevent a user from accidently allowlisitng a malicious extension. This policy allows you to specify which extensions are not subject to the blacklist. A blacklist value of ‘*’ means all extensions are blacklisted and users can only install extensions listed in the allowlist. By default, no extensions are allowlisted. If all extensions have been blacklisted by policy, then the allowlist policy can be used to allow specific extensions to be installed. Administrators should determine which extensions should be allowed to be installed by their users. If no extensions are allowlisted, then no extensions can be installed when combined with blacklisting all extensions.

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

IA Controls

NIST SP 800-53

Not mappedCCI-001170SV-57563V-44729

References

DPMS Target Google Chrome Current Windows DISA DPMS Target Google Chrome Current Windows 4081

Checks

DISA STIG (Manual Reference)

Universal method: 
1. In the omnibox (address bar) type chrome://policy 
2. If ExtensionInstallAllowlist is not displayed under the Policy Name column or it is not set to oiigbmnaadbkfbmpbfijlflahbdbdgdf or a list of administrator approved extension IDs, then this is a finding.

Windows method:
1. Start regedit
2. Navigate to the key HKLM\Software\Policies\Google\Chrome\ExtensionInstallAllowlist
3. If the ExtensionInstallAllowlist key is not set to 1 and oiigbmnaadbkfbmpbfijlflahbdbdgdf or a list of administrator-approved extension IDs, then this is a finding.

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.stig.chrome:def:240006
# Extensions that are approved for use must be allowlisted.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# Extensions that are approved for use are allowlisted
# registry_object (registry_test)
function test_1 {
  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\Google\Chrome\ExtensionInstallAllowlist').GetValueKind('1').ToString()]) -eq 'reg_sz') -and (((Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Google\Chrome\ExtensionInstallAllowlist' -Name '1' -ErrorAction SilentlyContinue) | Select-Object -ExpandProperty '1') -eq 'oiigbmnaadbkfbmpbfijlflahbdbdgdf'))
}

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

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 google_chrome target this check assesses.

# OVAL Definition: oval:mil.disa.stig.chrome:def:240006
$compliant = Test-Path -Path "HKLM:\Software\Policies\Google\Chrome\ExtensionInstallAllowlist" -and (Get-ItemProperty -Path "HKLM:\Software\Policies\Google\Chrome\ExtensionInstallAllowlist" -ErrorAction SilentlyContinue).1 -eq "oiigbmnaadbkfbmpbfijlflahbdbdgdf"
if ($compliant) { Write-Output "PASS"; Exit 0 } else { Write-Output "FAIL"; Exit 1 }

Remediation

Windows group policy:
1. Open the group policy editor tool with gpedit.msc 
2. Navigate to Policy Path: Computer Configuration\Administrative Templates\Google\Google Chrome\Extensions\
Policy Name: Configure extension installation allowlist
Policy State: Enabled
Policy Value: oiigbmnaadbkfbmpbfijlflahbdbdgdf

Note: oiigbmnaadbkfbmpbfijlflahbdbdgdfis the extension ID for scriptno (a commonly used Chrome extension), other extension IDs may vary.