Everyone Full Control Security Risks

Few permission configurations are as dangerous as granting Full Control to the Everyone group. This single misconfiguration can expose your entire file system to unauthorized access, data theft, ransomware attacks, and compliance violations. Yet it remains surprisingly common in enterprise environments.

This guide explains why "Everyone Full Control" is a critical security risk, how to find these vulnerabilities across your file system, and the proper way to remediate them without breaking applications or business processes.

Understanding the Risk

What is the "Everyone" Group?

The Everyone group is a built-in Windows security principal that includes:

• All authenticated domain users
• All local users
• Guest accounts (if enabled)
• Anonymous users (in certain configurations)

When you grant permissions to Everyone, you're essentially removing access control entirely. Any person who can reach your file server - whether a trusted employee, a contractor, a compromised account, or potentially an anonymous attacker - gains the specified access.

Why Full Control Makes It Worse

Full Control is the most permissive NTFS right, encompassing:

• Read - View file contents and attributes
• Write - Modify file contents
• Delete - Remove files and folders
• Change Permissions - Modify the ACL itself
• Take Ownership - Claim ownership of objects

Critical Risk: The "Change Permissions" right means anyone can modify the security settings, potentially locking out administrators or granting additional access to malicious actors.

Real-World Consequences

Organizations with Everyone Full Control permissions face:

• Ransomware devastation - Attackers can encrypt all accessible files
• Data exfiltration - Sensitive data can be copied by any user
• Compliance failures - Automatic failure of SOX, HIPAA, PCI-DSS, GDPR audits
• Insider threats - Disgruntled employees can delete or modify critical data
• No forensic trail - When everyone has access, you can't determine who did what

Common Sources of Everyone Full Control

Understanding how these permissions appear helps prevent future occurrences:

Legacy System Migrations

Older versions of Windows had more permissive defaults. Data migrated from Windows NT, Windows 2000, or early Windows Server versions often retains these legacy permissions.

Troubleshooting Shortcuts

When users report "Access Denied" errors, busy administrators sometimes grant Everyone Full Control as a quick fix, intending to revisit the issue later. These temporary fixes become permanent security holes.

Application Requirements

Some poorly designed applications require overly permissive access to shared folders. Administrators may grant Everyone Full Control to make the application work without understanding the security implications.

User-Created Shares

When end users create shares on their workstations or in user-accessible areas, they often use the default permissions or select Everyone for convenience.

Finding Everyone Full Control with Permissions Reporter

Permissions Reporter includes a built-in filter preset specifically designed to locate folders where Everyone has been granted Full Control. Here's how to use it:

Step 1: Create or Open a Project

1. Launch Permissions Reporter
2. Create a new project or open an existing one
3. Add the folder paths you want to audit (file servers, shared drives, etc.)
4. Run the permissions scan

Step 2: Apply the Everyone Full Control Filter

1. After the scan completes, click the Filter dropdown in the main toolbar
2. Select Edit Post-Scan Filter to open the filter editor
3. In the filter editor toolbar, click the Quick button
4. Select "Permissions allowing 'everyone' full control" from the quick filter menu
5. Click Apply to filter the results

What the filter finds: This preset identifies any folder or file where the Everyone group (or equivalent principals like "Authenticated Users" with Full Control) has been granted Full Control rights, whether through explicit assignment or inheritance.

Step 3: Review and Prioritize Results

The filtered view shows all locations with Everyone Full Control. Prioritize remediation based on:

• Data sensitivity - Financial, HR, healthcare, or customer data first
• Exposure level - Network shares accessible from multiple locations
• Inheritance scope - Root folders affect all children
• Business criticality - Production systems before development

Step 4: Export for Remediation Planning

Export the findings for your remediation project:

1. Click Export in the toolbar
2. Choose Excel format for remediation tracking
3. Use the export as your remediation checklist
4. Save a copy as audit evidence for compliance

Remediation Strategies

Option 1: Replace with Specific Security Groups

The best approach is to replace Everyone with purpose-specific security groups:

1. Identify who actually needs access - Determine the legitimate users
2. Create appropriate security groups - e.g., "Finance-ReadWrite", "HR-FullControl"
3. Assign minimum necessary permissions - Read-only where possible
4. Remove Everyone - After testing with the new groups

# PowerShell: Replace Everyone with a specific group
$path = "D:\SharedData\Finance"
$acl = Get-Acl $path

# Remove Everyone
$everyoneRule = $acl.Access | Where-Object { $_.IdentityReference -eq "Everyone" }
if ($everyoneRule) {
    $acl.RemoveAccessRule($everyoneRule)
}

# Add specific group with appropriate permissions
$group = "DOMAIN\Finance-Users"
$permission = "Modify"  # Not Full Control!
$rule = New-Object System.Security.AccessControl.FileSystemAccessRule(
    $group, $permission, "ContainerInherit,ObjectInherit", "None", "Allow"
)
$acl.AddAccessRule($rule)

Set-Acl $path $acl

Option 2: Downgrade to Lesser Permissions

If broad access is legitimately required, downgrade from Full Control:

• Modify - Read, write, delete, but can't change permissions
• Read & Execute - View and run, but not modify
• Read - View only

Best practice: Even when broad access is needed, never grant Full Control. Use Modify at most, which prevents users from changing permissions or taking ownership.

Option 3: Replace Everyone with Authenticated Users

As an intermediate step, replace Everyone with Authenticated Users to at least exclude anonymous and guest access:

# Replace Everyone with Authenticated Users (same permissions)
$path = "D:\PublicShare"
$acl = Get-Acl $path

# Get Everyone's current permissions
$everyoneRule = $acl.Access | Where-Object {
    $_.IdentityReference -eq "Everyone" -and $_.AccessControlType -eq "Allow"
}

if ($everyoneRule) {
    # Create equivalent rule for Authenticated Users
    $authUsersRule = New-Object System.Security.AccessControl.FileSystemAccessRule(
        "Authenticated Users",
        $everyoneRule.FileSystemRights,
        $everyoneRule.InheritanceFlags,
        $everyoneRule.PropagationFlags,
        "Allow"
    )

    $acl.RemoveAccessRule($everyoneRule)
    $acl.AddAccessRule($authUsersRule)
    Set-Acl $path $acl
}

Prevention: Stopping Future Occurrences

Implement Change Control

Require approval for permission changes on critical file systems:

• Document all permission change requests
• Require security review for broad access grants
• Prohibit Everyone and Full Control without executive approval

Regular Auditing Schedule

Schedule recurring scans to catch new vulnerabilities:

• Use Permissions Reporter's built-in scheduler
• Run weekly scans on critical file servers
• Configure email alerts for new findings
• Use report comparison to track changes

User Education

Train administrators and power users on:

• The principle of least privilege
• Proper use of security groups
• The dangers of "quick fix" permission grants
• How to request proper access for applications

Compliance Considerations

Everyone Full Control permissions affect compliance with multiple regulations:

• HIPAA - Requires access controls on protected health information
• PCI-DSS - Mandates restricted access to cardholder data
• SOX - Requires access controls on financial data
• GDPR - Requires appropriate security for personal data
• NIST/CIS - Security frameworks explicitly prohibit overly permissive access

Audit evidence: Permissions Reporter exports serve as documentation that you've identified and remediated security vulnerabilities - valuable evidence for compliance audits.

Related Resources

• Advanced Filtering in Permissions Reporter
• NTFS Permissions Overview
• NTFS Permissions Best Practices
• Finding Orphaned SIDs and Deleted Accounts
• NTFS Security & Compliance FAQ