Ensure Unlisted File Extensions are not allowed

MoyenneNiveau 1Automatiséeiis

Description

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.

Méthode de vérification

Méthode d'audit: Commande 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' }

Sortie attendue: compliant

Méthode de correction

Méthode de correction: Recommandation ou correctif d'infrastructure

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)

Propriétés

Systèmes d'exploitation: Tous
Étiquettes: iisrequest-filtering
Référence: CIS Microsoft IIS 10 Benchmark v1.2.1 - 4.7 Ensure Unlisted File Extensions are not allowed

Vérifier cet hôte

Exécutez cette commande sur une machine que vous êtes autorisé à auditer. L'analyse est en lecture seule.

shell

tmaegis scan --target iis