TMA-IIS-4.5

Ensure Double-Encoded requests will be rejected

보통레벨 1자동iis

설명

This Request Filter feature prevents attacks that rely on double-encoded requests and applies if an attacker submits a double-encoded request to IIS. When the double- encoded requests filter is enabled, IIS will go through a two iteration process of normalizing the request. If the first normalization differs from the second, the request is rejected and the error code is logged as a 404.11. requestFiltering allowDoubleEscaping must be false at server level and for every site. PowerShell 5.1 with the WebAdministration module; run elevated.

점검 방법

감사 방식: 셸 명령

shell

Import-Module WebAdministration -ErrorAction Stop; $paths = @('MACHINE/WEBROOT/APPHOST') + @(Get-Website | ForEach-Object { "IIS:\Sites\$($_.Name)" }); $bad = @($paths | Where-Object { $c = Get-WebConfiguration -Filter 'system.webServer/security/requestFiltering' -PSPath $_; $c.allowDoubleEscaping -ne $false }); if ($bad.Count -eq 0) { 'compliant' } else { 'noncompliant' }

예상 출력: compliant

조치 방법

조치 방식: 가이드 또는 인프라 패치

Set-WebConfigurationProperty -PSPath 'MACHINE/WEBROOT/APPHOST' -Filter system.webServer/security/requestFiltering -Name allowDoubleEscaping -Value False

속성

운영 체제: 모두
태그: iisrequest-filtering
참고 자료: CIS Microsoft IIS 10 Benchmark v1.2.1 - 4.5 Ensure Double-Encoded requests will be rejected

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감사 권한이 있는 시스템에서 실행하세요. 스캔은 읽기 전용입니다.

shell

tmaegis scan --target iis