TMA-IIS-6.2
Ensure FTP Logon attempt restrictions is enabled
Description
FTP Logon attempt restrictions is a built-in network security feature to automatically block brute force FTP attacks. This can be used to mitigate a malicious client from attempting a brute-force attack on a discovered account, such as the local administrator account. FTP logon attempt restrictions (system.ftpServer/security/authentication/denyByFailure enabled) must be on. Not applicable when the FTP service is not installed. PowerShell 5.1 with the WebAdministration module; run elevated. CIS marks this recommendation Manual; the automated check implements its audit procedure.
How it is checked
Audit method: Shell command
Import-Module WebAdministration -ErrorAction Stop; $c = Get-WebConfiguration -Filter 'system.ftpServer/security/authentication/denyByFailure' -PSPath 'MACHINE/WEBROOT/APPHOST'; if ($c.enabled -eq $true) { 'compliant' } else { 'noncompliant' }- Expected output
compliant
How it is fixed
Fix method: Guidance or infrastructure patch
Set-WebConfigurationProperty -PSPath 'MACHINE/WEBROOT/APPHOST' -Filter system.ftpServer/security/authentication/denyByFailure -Name enabled -Value True (set maxFailure and entryExpiration as required)
Properties
- Operating systems
- Any
- Tags
- iisftp
- Reference
- CIS Microsoft IIS 10 Benchmark v1.2.1 - 6.2 Ensure FTP Logon attempt restrictions is enabled
Check this host
Run this on a machine you are allowed to audit. The scan is read-only.
tmaegis scan --target iis