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Security ​

PoshUI is designed with security as a core principle. This page outlines the security features and best practices when using PoshUI in your environment.

Code Signing ​

All PoshUI executables are digitally signed with an Extended Validation (EV) certificate to ensure authenticity and integrity.

Verification ​

You can verify the digital signature of PoshUI executables:

powershell
# Verify the signature
Get-AuthenticodeSignature -FilePath ".\PoshUI.exe"

# Check signature status
$sig = Get-AuthenticodeSignature -FilePath ".\PoshUI.exe"
if ($sig.Status -eq 'Valid') {
    Write-Host "Signature is valid" -ForegroundColor Green
    Write-Host "Signer: $($sig.SignerCertificate.Subject)"
}

Why Code Signing Matters ​

  • Authenticity: Confirms the executable comes from Kanders-II
  • Integrity: Ensures the file hasn't been tampered with since signing
  • Trust: Windows SmartScreen and antivirus software recognize signed executables
  • Compliance: Meets enterprise security policies requiring signed code

Execution Model ​

PowerShell Execution ​

PoshUI executes PowerShell scripts in isolated runspaces with the following security characteristics:

  • Isolated Sessions: Each script execution runs in its own PowerShell runspace
  • No Persistent State: Scripts cannot access variables or state from other executions
  • User Context: Scripts run with the permissions of the user who launched PoshUI
  • No Elevation: PoshUI does not automatically elevate privileges

Script Validation ​

When you provide scripts to PoshUI:

  1. AST Parsing: Scripts are parsed using PowerShell's Abstract Syntax Tree parser
  2. Parameter Discovery: Only parameter definitions are extracted for UI generation
  3. No Pre-Execution: Scripts are not executed until the user explicitly triggers them
  4. User Confirmation: ScriptCards require user interaction before execution

Data Handling ​

Input Validation ​

  • Type Safety: Parameters are validated against their declared types
  • Attribute Validation: PowerShell validation attributes ([ValidateSet], [ValidateRange], etc.) are enforced
  • Mandatory Fields: Required parameters are enforced before script execution
  • Path Validation: File and folder paths are validated for existence when appropriate

Data Storage ​

  • No Persistent Storage: PoshUI does not store user input or script results
  • Temporary Files: Generated scripts are written to $env:TEMP and cleaned up after execution
  • Memory Only: UI state and data exist only in memory during runtime
  • No Telemetry: PoshUI does not collect or transmit usage data

Network Security ​

No External Dependencies ​

  • Offline Operation: PoshUI works completely offline with no internet requirement
  • No Phone Home: No telemetry, analytics, or update checks
  • No External Libraries: Zero third-party dependencies that could introduce supply chain risks
  • Air-Gapped Compatible: Fully functional in isolated networks

Script Network Access ​

Scripts executed by PoshUI have the same network access as the user:

  • PoshUI does not restrict or enable network access
  • Scripts inherit the user's network permissions and proxy settings
  • Firewall rules and network policies apply normally

Execution Policy ​

PoshUI respects PowerShell's execution policy:

powershell
# Check current execution policy
Get-ExecutionPolicy

# PoshUI requires one of these policies:
# - RemoteSigned (recommended)
# - Unrestricted
# - Bypass
powershell
# Set execution policy for current user (no admin required)
Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser

Best Practices ​

For Script Authors ​

  1. Validate Input: Use PowerShell validation attributes on parameters
  2. Least Privilege: Don't require admin rights unless absolutely necessary
  3. Error Handling: Use try/catch blocks to handle errors gracefully
  4. Logging: Log actions for audit trails when appropriate
  5. Sensitive Data: Avoid hardcoding credentials or secrets in scripts

For IT Administrators ​

  1. Code Review: Review scripts before deploying them in ScriptCards
  2. Access Control: Use NTFS permissions to control who can run PoshUI scripts
  3. Audit Logging: Enable PowerShell script block logging for audit trails
  4. Network Isolation: Deploy PoshUI tools on appropriate network segments
  5. Regular Updates: Keep PoshUI updated to receive security improvements

For End Users ​

  1. Verify Signature: Check that PoshUI.exe is properly signed before running
  2. Trusted Sources: Only run PoshUI scripts from trusted IT sources
  3. Review Output: Monitor script output for unexpected behavior
  4. Report Issues: Report suspicious behavior to your IT security team

Security Considerations ​

What PoshUI Does NOT Do ​

  • ❌ Does not bypass Windows security features
  • ❌ Does not elevate privileges automatically
  • ❌ Does not disable antivirus or security software
  • ❌ Does not access the internet or send data externally
  • ❌ Does not store credentials or sensitive data
  • ❌ Does not modify system files or registry without explicit script commands

What PoshUI DOES Do ​

  • ✅ Executes PowerShell scripts with user's current permissions
  • ✅ Validates input before passing to scripts
  • ✅ Isolates script executions in separate runspaces
  • ✅ Provides a signed, trusted executable
  • ✅ Respects Windows security policies and execution policies
  • ✅ Operates transparently with no hidden functionality

Reporting Security Issues ​

If you discover a security vulnerability in PoshUI, please report it responsibly:

  1. Do not create a public GitHub issue
  2. Email security details to: [security contact - to be added]
  3. Include steps to reproduce the issue
  4. Allow time for a fix before public disclosure

We take security seriously and will respond promptly to legitimate security concerns.

Compliance ​

PoshUI is designed to support enterprise security requirements:

  • Code Signing: All executables are EV signed
  • Audit Trail: Compatible with PowerShell script block logging
  • No Data Leakage: No external communication or data storage
  • Transparent Operation: Open source code available for review
  • Standard Permissions: Works with standard user permissions (scripts may require elevation)

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