Ensure 'Control use of the File System API for writing' is set to 'Enabled: Don't allow any site to request write access to files and directories'

MediaNivel 1Automatizadaedge

Descripción

This policy setting specifies whether websites can ask for write access to the host operating system´s filesystem using the File System API. By default, websites can ask for access. Users can change this setting. By setting this policy to (2), access is denied. The recommended state for this setting is: Enabled: Don't allow any site to request write access to files and directories. Rationale: There is a large category of attack vectors that are opened by allowing web applications access to files. By setting this policy to Enabled: Don't allow any site to request write access to files and directories implements additional protection to safeguard against accidental sharing of sensitive inf... 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\Microsoft\Edge:DefaultFileSystemWriteGuardSetting (REG_DWORD); compliant when it is 2. Remediation writes 2 locally; in a domain set it through the ADMX so Group Policy does not revert it.

Cómo se verifica

Método de auditoría: Registro de Windows

registry

$v = (Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Edge' -Name 'DefaultFileSystemWriteGuardSetting' -ErrorAction SilentlyContinue).'DefaultFileSystemWriteGuardSetting'; if ($null -eq $v) { 'unset' } elseif (($null -ne $v -and @(2) -contains [int64]$v)) { 'compliant' } else { "non-compliant: $v" }

Salida esperada: compliant

Cómo se corrige

Método de corrección: Comando de shell

shell

$p = 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Edge'; if (-not (Test-Path -Path $p)) { New-Item -Path $p -Force | Out-Null }; New-ItemProperty -Path $p -Name 'DefaultFileSystemWriteGuardSetting' -Value 2 -PropertyType DWord -Force | Out-Null

Propiedades

Sistemas operativos: Cualquiera
Etiquetas: edgebrowsercis-l1
Referencia: CIS Microsoft Edge Benchmark v5.0.0 - 1.4.6 Ensure 'Control use of the File System API for writing' is set to 'Enabled: Don't allow any site to request write access to files and directories'

Verificar este host

Ejecute esto en un equipo que tenga permiso para auditar. El escaneo es de solo lectura.

shell

tmaegis scan --target edge