[REQ-END-101] Configure User Rights: Change the system time

Target Scope

  • Applicable Systems: Tier 2 client workstations and member servers. (For Domain Controllers, refer to REQ-DC-112).
  • Operating Systems: Windows 10 Enterprise/Professional (1809 and above), Windows 11 Enterprise/Pro, Windows Server 2016, 2019, 2022, and 2025.

Implementation Details

  • Priority: Medium
  • GPO Path / Registry Location:
    • Policy Display Name: Change the system time
    • Privilege Constant: SeSystemtimePrivilege
    • GPO Path: Computer Configuration\Policies\Windows Settings\Security Settings\Local Policies\User Rights Assignment\Change the system time
    • Registry Location: Stored inside local security database under privilege SeSystemtimePrivilege set to *S-1-5-32-544 (Administrators), *S-1-5-19 (LocalService).

Rationale

The SeSystemtimePrivilege allows a security principal to adjust the internal hardware clock and system time of the computer via Win32 APIs SetSystemTime or SetLocalTime. Accurate time synchronization is foundational to the Windows distributed security architecture.

1. Technical Threat Vector & Abuse Mechanics

Adversaries exploit system time alteration to defeat cryptographic protocols, authentication mechanisms, and forensic logging: (1) Kerberos Authentication Subversion: Kerberos tickets have strict timestamp validity windows (default 5-minute allowable skew). Tampering with system time can trigger ticket replay attacks, force ticket invalidation, or induce authentication bypasses; (2) Timestomping and Anti-Forensics: Modifying system time corrupts log event timestamps, confusing SIEM correlation pipelines, incident timelines, and forensic evidence collection; (3) Bypassing Security Policies: Time manipulation can prematurely expire smart card certificates, bypass account lockout cooldowns, or invalidate password age policies.

2. Architectural Defense & Least Privilege Enforcement

On general workstations and member servers, enforcing least privilege for this user right is critical for host isolation. Preventing unprivileged users or rogue applications from exercising this right stops local privilege escalation (LPE) and blocks adversaries from leveraging co-located user sessions to harvest credentials or pivot across the corporate subnet.

On Endpoints and Domain Controllers, SeSystemtimePrivilege must be restricted exclusively to Administrators (S-1-5-32-544) and LocalService (S-1-5-19) (which hosts the Windows Time service W32Time). Standard users and unprivileged applications must never possess system time modification rights.

3. MITRE ATT&CK Mapping

  • T1558 - Steal or Forge Kerberos Tickets
  • T1070.006 - Indicator Removal: Timestomp
  • T1562 - Impair Defenses

Legacy Impact & Compatibility

  • Operational Impact: Restricting SeSystemtimePrivilege ensures time integrity across domain workstations and servers. Time synchronization occurs automatically via the Windows Time service against Domain Controllers (NTP). Manual clock adjustments by administrators are logged under Security Event ID 4616 ('The system time was changed').

Implementation Steps

Option A: Group Policy Object (GPO) Configuration (Preferred)

  1. Open the Group Policy Management Console (gpmc.msc).
  2. Navigate to the targeted GPO linked to Tier 2 systems (e.g., GPO_Hardening_Endpoints).
  3. In the console tree, browse to: Computer Configuration\Policies\Windows Settings\Security Settings\Local Policies\User Rights Assignment
  4. Open the policy Change the system time.
  5. Select the Define these policy settings check box.
  6. Configure the security principal allocation to: *S-1-5-32-544 (Administrators), *S-1-5-19 (LocalService).
  7. Click Apply and OK.
  8. Apply and verify policy enforcement across target hosts using gpupdate /force and inspect with secedit /export /cfg C:\Windows\Temp\sec_audit.cfg.

Option B: PowerShell & Registry Configuration (Remediation / Non-GPO)

Download Script: Configure-UraSeSystemtimePrivilege.ps1

# Configure-UraSeSystemtimePrivilege.ps1
$SecTempDir = Join-Path $env:TEMP "SecurityTemplates"
if (-not (Test-Path $SecTempDir)) { New-Item -Path $SecTempDir -ItemType Directory -Force | Out-Null }
$CfgFile = Join-Path $SecTempDir "ura_sesystemtimeprivilege.cfg"
$DbFile = Join-Path $SecTempDir "secedit_sesystemtimeprivilege.sdb"
$LogFile = Join-Path $SecTempDir "secedit.log"

$Process = Start-Process secedit -ArgumentList "/export /cfg `"$CfgFile`"" -Wait -NoNewWindow -PassThru
if ($Process.ExitCode -ne 0) { Throw "Failed to export security template" }

$ConfigText = Get-Content -Path $CfgFile -Raw
if ($ConfigText -notmatch "\[Privilege Rights\]") {
    $ConfigText += "`r`n[Privilege Rights]`r`n"
}

$Lines = $ConfigText -split "`r?`n"
$NewLines = @()
$InPriv = $false
$KeyAdded = $false

foreach ($Line in $Lines) {
    if ($Line -match "^\[(.*)\]$") {
        if ($Matches[1] -eq "Privilege Rights") {
            $InPriv = $true
        } else {
            $InPriv = $false
        }
    }
    if ($InPriv -and $Line -match "^\s*SeSystemtimePrivilege\s*=") {
        $NewLines += "SeSystemtimePrivilege = *S-1-5-32-544,*S-1-5-19"
        $KeyAdded = $true
    } else {
        $NewLines += $Line
    }
}

if (-not $KeyAdded) {
    # Find Privilege Rights section index and insert it right after
    $Idx = $NewLines.IndexOf("[Privilege Rights]")
    if ($Idx -ge 0) {
        $NewLines.Insert($Idx + 1, "SeSystemtimePrivilege = *S-1-5-32-544,*S-1-5-19")
    } else {
        $NewLines += "SeSystemtimePrivilege = *S-1-5-32-544,*S-1-5-19"
    }
}

$NewLines | Set-Content -Path $CfgFile -Force
$Proc = Start-Process secedit -ArgumentList "/configure /db `"$DbFile`" /cfg `"$CfgFile`" /areas USER_RIGHTS /log `"$LogFile`"" -Wait -NoNewWindow -PassThru
if ($Proc.ExitCode -ne 0) { Throw "Failed to configure secedit user rights" }
Remove-Item -Path $CfgFile, $DbFile -ErrorAction SilentlyContinue

To audit the hardening status: Download Script: Get-UraSeSystemtimePrivilegeStatus.ps1

# Get-UraSeSystemtimePrivilegeStatus.ps1
$SecTempDir = Join-Path $env:TEMP "SecurityTemplates"
if (-not (Test-Path $SecTempDir)) { New-Item -Path $SecTempDir -ItemType Directory -Force | Out-Null }
$CfgFile = Join-Path $SecTempDir "ura_audit_sesystemtimeprivilege.cfg"

$Process = Start-Process secedit -ArgumentList "/export /cfg `"$CfgFile`"" -Wait -NoNewWindow -PassThru
if ($Process.ExitCode -ne 0) {
    Write-Output "Non-Compliant"
    exit 1
}

$ConfigText = Get-Content -Path $CfgFile -Raw
Remove-Item -Path $CfgFile -ErrorAction SilentlyContinue

$Match = $ConfigText -match "(?mi)^\s*SeSystemtimePrivilege\s*=\s*(.*)$"
$CurrentValue = ""
if ($Match) {
    $CurrentValue = $Matches[1].Trim()
}

$Expected = "*S-1-5-32-544,*S-1-5-19"
if ($CurrentValue -eq $Expected) {
    Write-Output "Compliant"
    exit 0
} else {
    Write-Output "Non-Compliant"
    exit 1
}

Sources & Compliance References

  • ANSSI Active Directory Hardening Guide: ANSSI Active Directory Hardening Guide: R28 (User Rights Assignment)
  • CIS Benchmark: 2.2.12 (L1) Ensure 'Change the system time' is set to 'Administrators, LOCAL SERVICE'
  • Microsoft Security Baseline: User Rights Configuration specifications
  • Microsoft Learn: User Rights Assignment Reference

results matching ""

    No results matching ""