TMA-IIS-4.7

Ensure Unlisted File Extensions are not allowed

MediaNivel 1Automatizadaiis

Descripción

The FileExtensions Request Filter allows administrators to define specific extensions their web server(s) will allow and disallow. The property allowUnlisted will cover all other file extensions not explicitly allowed or denied. Often times, extensions such as .config, .bat, .exe, to name a few, should never be served. The AllowExtensions and DenyExtensions options are the UrlScan equivalents. requestFiltering fileExtensions allowUnlisted must be false at server level (then allow only required extensions). PowerShell 5.1 with the WebAdministration module; run elevated.

Cómo se verifica

Método de auditoría: Comando de shell

shell

Import-Module WebAdministration -ErrorAction Stop; $c = Get-WebConfiguration -Filter 'system.webServer/security/requestFiltering/fileExtensions' -PSPath 'MACHINE/WEBROOT/APPHOST'; if ($c.allowUnlisted -eq $false) { 'compliant' } else { 'noncompliant' }

Salida esperada: compliant

Cómo se corrige

Método de corrección: Guía o parche de infraestructura

Set-WebConfigurationProperty -PSPath 'MACHINE/WEBROOT/APPHOST' -Filter system.webServer/security/requestFiltering/fileExtensions -Name allowUnlisted -Value False (after adding <add fileExtension='.aspx' allowed='true'/> etc. for required types)

Propiedades

Sistemas operativos: Cualquiera
Etiquetas: iisrequest-filtering
Referencia: CIS Microsoft IIS 10 Benchmark v1.2.1 - 4.7 Ensure Unlisted File Extensions are not allowed

Verificar este host

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

shell

tmaegis scan --target iis