SV-25072r1: The system is not configured to use Safe DLL search mode. | Windows 7 Security Technical Implementation Guide

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Assessment Title

Rule Text

The system is not configured to use Safe DLL search mode.

Description

Discussion Text

The default search behavior, when an application calls a function in a Dynamic Link Library (DLL), is to search the current directory followed by the directories contained in the systems path environment variable. An unauthorized DLL, inserted into an applications working directory, could allow malicious code to be run on the system. Setting this policy value forces the system to search the %Systemroot% for the DLL before searching the current directory or the rest of the path.

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

IA Controls

NIST SP 800-53

Not mappedCCI-000366CCE-9348-4

Additional Details

Third-Party Tools

Responsibility

System Administrator

References

DPMS Target Windows 7 DISA DPMS Target Windows 7 1712

Checks

OVAL

oval:mil.disa.fso.windows:var:374200 ← xccdf_mil.disa.stig_value_safe_dll_search_mode_var

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:3742
# The system is not configured to use Safe DLL search mode.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# Verifies 'MSS: (SafeDllSearchMode) Enable Safe DLL search mode (recommended)' is set to 'Enabled'
# registry_object (registry_test)
function test_1 {
  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\Session Manager').GetValueKind('SafeDllSearchMode').ToString()]) -eq 'reg_dword') -and (((Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager' -Name 'SafeDllSearchMode' -ErrorAction SilentlyContinue) | Select-Object -ExpandProperty 'SafeDllSearchMode') -eq 1))
}

if (test_1) {
  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_7 target this check assesses.

# oval:mil.disa.fso.windows:def:3742
if (Test-Path -Path "HKLM:\SYSTEM\CurrentControlSet\Control\Session Manager\SafeDllSearchMode" -and (Get-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Control\Session Manager\SafeDllSearchMode").SafeDllSearchMode -eq 1) { Write-Output "PASS"; Exit 0 } else { Write-Output "FAIL"; Exit 1 }

Remediation

Configure the policy value for Computer Configuration -> Windows Settings -> Security Settings -> Local Policies -> Security Options -> “MSS: (SafeDllSearchMode) Enable Safe DLL search mode (recommended)” to “Enabled”.