SV-28982r1: Anonymous shares are not restricted. | Windows Vista Security Technical Implementation Guide

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Assessment Title

Rule Text

Anonymous shares are not restricted.

Description

Discussion Text

This is a Category 1 finding because it allows anonymous logon users (null session connections) to list all account names and enumerate all shared resources, thus providing a map of potential points to attack the system.

How this relates to the STIG checklist: STIG vs SCAP benchmark.

IA Controls

NIST SP 800-53

Not mappedCCI-001090CCE-3272-2

Additional Details

Potential Impacts

In a mixed Windows environment this setting may cause systems with down-level operating systems to fail to authenticate, may prevent their users from changing their passwords, and may cause problems with managing printers and spools.

Responsibility

Information Assurance Officer

References

DPMS Target Windows Vista DISA DPMS Target Windows Vista 1029

SCC Automation Reference

The reconstructed evaluation script behind this rule's OVAL check(s) — every module a compound check combines, with this rule's own concrete values and DISA's SCC tool's real per-module mechanism curated from static teardown of SCC releases.

# Windows PowerShell
# Reconstructed from oval:mil.disa.fso.windows:def:416
# Anonymous shares are not restricted.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# registry_object (registry_test)
function test_1 {
  return (((Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Lsa' -Name 'RestrictAnonymous' -ErrorAction SilentlyContinue) | Select-Object -ExpandProperty 'RestrictAnonymous') -eq 1)
}
# registry_object (registry_test)
function test_2 {
  return (-not ($null -ne (Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Lsa' -Name 'RestrictAnonymous')))
}
# registry_object (registry_test)
function test_3 {
  return ((@{String='reg_sz';ExpandString='reg_expand_sz';Binary='reg_binary';DWord='reg_dword';MultiString='reg_multi_sz';QWord='reg_qword';None='reg_none'}[(Get-Item -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Lsa\').GetValueKind('RestrictAnonymous').ToString()]) -eq 'reg_dword')
}
# registry_object (registry_test)
function test_4 {
  return (-not ($null -ne (Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Lsa\' -Name 'RestrictAnonymous')))
}
# registry_object (registry_test)
function test_5 {
  return ($null -ne (Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Lsa\' -Name 'RestrictAnonymous'))
}
# registry_object (registry_test)
function test_6 {
  return (((Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Lsa' -Name 'restrictanonymoussam' -ErrorAction SilentlyContinue) | Select-Object -ExpandProperty 'restrictanonymoussam') -eq 1)
}
# registry_object (registry_test)
function test_7 {
  return (-not ($null -ne (Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Lsa' -Name 'restrictanonymoussam')))
}
# registry_object (registry_test)
function test_8 {
  return ((@{String='reg_sz';ExpandString='reg_expand_sz';Binary='reg_binary';DWord='reg_dword';MultiString='reg_multi_sz';QWord='reg_qword';None='reg_none'}[(Get-Item -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Lsa').GetValueKind('restrictanonymoussam').ToString()]) -eq 'reg_dword')
}
# registry_object (registry_test)
function test_9 {
  return (-not ($null -ne (Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Lsa' -Name 'restrictanonymoussam')))
}
# registry_object (registry_test)
function test_10 {
  return ($null -ne (Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Lsa' -Name 'restrictanonymoussam'))
}

if (((test_1 -or test_2) -and (test_3 -or test_4) -and test_5 -and (test_6 -or test_7) -and (test_8 -or test_9) -and test_10)) {
  Write-Output "PASS"
} else {
  Write-Output "FAIL"
}

Assessment Script Powered by AISyntax-verified

A standalone PowerShell script to assess this control automatically. Review before running it in your environment.

Syntax-checked as valid PowerShell. Not executed here — running it for real needs the actual windows_vista target this check assesses.

# OVAL Definition: oval:mil.disa.fso.windows:def:416
$compliant = (Get-ItemProperty -Path "HKLM:\System\CurrentControlSet\Control\Lsa" -Name "RestrictAnonymous" -ErrorAction SilentlyContinue).Value -eq 1 -or (Get-ItemProperty -Path "HKLM:\System\CurrentControlSet\Control\Lsa" -Name "RestrictAnonymousSAM" -ErrorAction SilentlyContinue).Value -eq 1
if ($compliant) {Write-Output "PASS"; exit 0} else {Write-Output "FAIL"; exit 1}

Remediation

Configure the policy values for Computer Configuration -> Windows Settings -> Security Settings -> Local Policies -> Security Options -> “Network access: Do not allow anonymous enumeration of SAM accounts” and “Network access: Do not allow anonymous enumeration of SAM accounts and shares” to “Enabled".