Microsoft IIS
TMA-IIS-7.10
Ensure AES 128/128 Cipher Suite is Disabled
MediumLevel 1Automatediis
Description
The AES 128/128 Cipher Suite is not considered secure and therefore should be disabled, if possible. SCHANNEL\Ciphers\AES 128/128 must exist with Enabled=0 (read via the .NET registry API because the key names contain "/"). PowerShell 5.1; reads the registry (run elevated).
How it is checked
Audit method: Windows registry
registry
$c = 'SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Ciphers'; function Get-Cipher($n) { $k = [Microsoft.Win32.Registry]::LocalMachine.OpenSubKey("$c\$n"); $v = $null; if ($k) { $v = $k.GetValue('Enabled'); $k.Close() }; $v }; $bad = @('AES 128/128' | Where-Object { $v = Get-Cipher $_; $null -eq $v -or [long]$v -ne 0 }); if ($bad.Count -eq 0) { 'compliant' } else { 'noncompliant' }- Expected output
compliant
How it is fixed
Fix method: Guidance or infrastructure patch
([Microsoft.Win32.Registry]::LocalMachine.CreateSubKey('SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Ciphers\AES 128/128')).SetValue('Enabled', 0, 'DWord') for each listed cipher (PowerShell drive paths cannot contain '/'), then reboot.
Properties
- Operating systems
- Any
- Tags
- iistls
- Reference
- CIS Microsoft IIS 10 Benchmark v1.2.1 - 7.10 Ensure AES 128/128 Cipher Suite is Disabled
Check this host
Run this on a machine you are allowed to audit. The scan is read-only.
shell
tmaegis scan --target iis