Ensure 'Allow Basic Authentication prompts from network proxies' is set to 'Disabled'

HighLevel 1Automatedintune-office

Description

Apps such as Word and Excel allow users to use Basic authentication to connect to resources on web servers by sending usernames and passwords with each request. These credentials are often stored on the servers, making it easier for attackers to capture them and reuse them against other endpoints or services. The recommended state for this setting is: Disabled. Note: This policy setting only applies to subscription versions of Office, such as Microsoft 365 Apps for enterprise, and to subscription versions of Project and Visio. Note 2: This change doesn’t affect Outlook connecting to on-premises Exchange Server using Basic authentication. ... Audit: reads the registry value(s) basicauthproxybehavior that the Intune policy writes for every loaded user profile (HKEY_USERS) and prints compliant only when each satisfies the benchmark value.

How it is checked

Audit method: Windows registry

registry

$bad = @(); $bad += @(Get-ChildItem Registry::HKEY_USERS | Where-Object { $_.PSChildName -match '^S-1-5-21-\d+-\d+-\d+-\d+$' } | ForEach-Object { $v = (Get-ItemProperty -Path ('Registry::HKEY_USERS\' + $_.PSChildName + '\SOFTWARE\Policies\Microsoft\office\16.0\common\identity') -Name 'basicauthproxybehavior' -ErrorAction SilentlyContinue).'basicauthproxybehavior'; if (-not ($null -ne $v -and @(0) -contains [int64]$v)) { $_.PSChildName + ':basicauthproxybehavior=' + $v } }); if ($bad.Count -eq 0) { 'compliant' } else { 'non-compliant: ' + ($bad -join ', ') }

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

To establish the recommended state via configuration profiles, set the following Settings Catalog path to Disabled: Microsoft Office 2016\Security Settings\Allow Basic Authentication prompts from network proxies

Properties

Operating systems: Any
Tags: intune-officeintuneregistry
Reference: CIS Microsoft Intune for Office Benchmark v1.1.0 - 2.3.27.5 Ensure 'Allow Basic Authentication prompts from network proxies' 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 intune-office