This document outlines security best practices, known issues, and procedures for the Front-End App project.

1. Security Standards
2. Known Issues & Remediation
3. Secrets Management
4. Dependency Security
5. Code Security
6. Data Protection
7. Authentication & Authorization
8. Incident Reporting
9. Security Checklist

This project follows:

• OWASP Top 10 vulnerability prevention
• NIST Cybersecurity Framework best practices
• CWE (Common Weakness Enumeration) mitigation
• PCI DSS compliance for payment handling (if applicable)

• Developers: Write secure code, follow standards
• Code Reviewers: Validate security in PRs
• Team Lead: Overall security oversight
• DevOps/Security: Infrastructure and secrets management

Status: ⚠️ ONGOING MAINTENANCE

Severity: MEDIUM

Problem:

• 50+ security patch overrides in pnpm configuration
• Indicates transitive dependencies with vulnerabilities
• Creates ongoing maintenance burden
• Masks underlying dependency issues

Examples:

• lodash pinned to <= 4.17.23 (multiple CVEs)
• tar override for security patches
• undici version constraints for fixes
• rollup, minimatch, yaml patches

Risk:

• Unpatched vulnerabilities in transitive dependencies
• Supply chain attack vector
• Difficult to track what vulnerabilities are mitigated

Action Items:

1. Audit current overrides:

   pnpm audit
   pnpm audit --json | jq '.advisories'

2. Review each override:

   {
     "overrides": {
       "lodash": ">=4.18.0", // ← Why is this needed?
       "tar": "^6.2.1" // ← Justification?
     }
   }

3. Reduce overrides incrementally:

   • Remove override
   • Run pnpm audit
   • If vulnerability found, document why override is needed
   • Only keep justified overrides

4. Document overrides:

   // pnpm-lock.yaml comments or separate doc
   /**
    * SECURITY OVERRIDES JUSTIFICATION
    *
    * lodash >= 4.18.0
    *   - Vulnerability: CVE-2021-23337
    *   - Affected: moment.js depends on vulnerable version
    *   - Why override: Can't upgrade moment.js yet
    *   - Review date: 2026-04-01
    */

5. Transition plan:

   • Remove 5 overrides per quarter
   • Upgrade dependencies that require removed overrides
   • Target: Reduce to 10 or fewer overrides

Deadline: Ongoing, review quarterly

Status: ⚠️ REVIEW CODE

Severity: MEDIUM (XSS Risk)

Problem:

• No centralized input validation
• User input not sanitized before display
• API responses not validated against schema
• Form inputs lack format validation

Risk:

• Cross-Site Scripting (XSS) attacks
• SQL Injection (if user input passed to backend)
• Buffer overflow / Denial of Service

Solution:

1. Create validation service:

   import { Injectable } from '@angular/core';
   
   @Injectable({ providedIn: 'root' })
   export class ValidationService {
     /**
      * Validates and sanitizes user input
      * @param input - Raw user input
      * @param type - Type of input (email, url, text, etc)
      * @returns Sanitized input or null if invalid
      */
     validateInput(input: string, type: 'email' | 'url' | 'text'): string | null {
       if (!input || typeof input !== 'string') return null;
   
       const trimmed = input.trim();
   
       switch (type) {
         case 'email':
           return /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(trimmed) ? trimmed : null;
         case 'url':
           try {
             new URL(trimmed);
             return trimmed;
           } catch {
             return null;
           }
         case 'text':
           return trimmed.length > 0 && trimmed.length <= 5000 ? trimmed : null;
       }
     }
   }

2. Use Angular sanitization:

   import { Component, inject } from '@angular/core';
   import { DomSanitizer, SafeHtml } from '@angular/platform-browser';
   
   @Component({
     selector: 'app-article-display',
     template: `<div [innerHTML]="sanitizedHtml"></div>`,
   })
   export class ArticleDisplayComponent {
     private readonly sanitizer = inject(DomSanitizer);
   
     htmlContent: string = '<script>alert("xss")</script><p>Safe content</p>';
   
     get sanitizedHtml(): SafeHtml {
       return this.sanitizer.sanitize(SecurityContext.HTML, this.htmlContent) ?? '';
     }
   }

3. Validate API responses:

   import { Injectable } from '@angular/core';
   
   @Injectable()
   export class ArticleService {
     private validateArticle(article: unknown): article is Article {
       if (typeof article !== 'object' || !article) return false;
   
       const a = article as any;
       return (
         typeof a.id === 'string' &&
         typeof a.title === 'string' &&
         typeof a.description === 'string'
       );
     }
   
     getArticles(): Observable<Article[]> {
       return this.http.get<unknown[]>('/api/articles').pipe(
         map((data) => {
           if (!Array.isArray(data)) throw new Error('Invalid API response');
           return data.filter(this.validateArticle);
         }),
         catchError((err) => throwError(() => new Error('Failed to fetch'))),
       );
     }
   }

Deadline: 4 weeks

Production:

• Vercel: Project Settings → Environment Variables
• Render: Environment Groups
• Docker: Use --env-file or orchestration secrets
• Never commit secrets to git

.env.*.local
.env
.env.production
.env.test
*.pem (private keys)
*.key (keys)
aws_credentials
api_keys
credentials.json
secrets.yml

# Audit current dependencies
pnpm audit

# Fix known vulnerabilities
pnpm audit --fix

# Check for outdated packages
pnpm outdated

# Update to latest
pnpm update --latest

# Update minor/patch versions only (safe)
pnpm update

# Update to specific version
pnpm update package-name@latest

# Review changes before committing
git diff package.json pnpm-lock.yaml

• Critical Vulnerabilities: Fix within 24 hours
• High Vulnerabilities: Fix within 1 week
• Medium Vulnerabilities: Fix within 2 weeks
• Low Vulnerabilities: Fix during next sprint

• Use exact versions in package.json (no ^ or ~)
• Verify package integrity with pnpm integrity
• Review package licenses (avoid GPL in closed source)
• Check package maintainers and activity

❌ Bad:

const apiKey = 'sk-abc123def456';
const password = 'admin123';
const token = 'eyJhbGciOi...';

✅ Good:

const apiKey = process.env['API_KEY'];
const password = process.env['PASSWORD'];
const token = sessionStorage.getItem('auth_token');

❌ Bad:

template: `<div [innerHTML]="userInput"></div>`;

✅ Good:

import { DomSanitizer } from '@angular/platform-browser';

template: `<div [innerHTML]="sanitizer.sanitize(SecurityContext.HTML, userInput)"></div>`;

• Use CSRF tokens for state-changing operations
• Angular HttpClient automatically handles CSRF for most cases
• Verify origin headers on backend

• Always use parameterized queries on backend
• Never concatenate user input into SQL
• Validate input length and format

• Disable XML entity expansion in parsers
• Use safe XML libraries
• Validate XML structure

// ✅ Safe: SessionStorage clears when tab closes
sessionStorage.setItem('auth_token', token);

// ❌ Unsafe: localStorage persists indefinitely
localStorage.setItem('auth_token', token);

// ❌ Extremely Unsafe: Global variable
window.authToken = token;

• Don't cache sensitive data longer than necessary
• Clear auth tokens on logout
• Clear forms after successful submission
• Remove temporary data after use

Secure Configuration:

import { ClerkService } from '@clerk/clerk-js';

// ✅ Use publishable key (safe to expose)
const clerk = new ClerkService({
  publishableKey: environment.clerkPublishableKey,
});

// ❌ Never use secret key in frontend
const secretKey = 'sk_live_...'; // WRONG! Never expose

/**
 * Best practices for JWT handling in Angular
 */

// ✅ Store in sessionStorage (cleared on tab close)
sessionStorage.setItem('access_token', jwt);

// ✅ Include in Authorization header
headers: new HttpHeaders({
  'Authorization': `Bearer ${token}`
});

// ✅ Refresh token before expiry
const expiresAt = jwt_decode(token).exp * 1000;
if (Date.now() + 5000 > expiresAt) {
  // Refresh token before it expires
}

// ✅ Remove on logout
logout() {
  sessionStorage.removeItem('access_token');
  this.router.navigate(['/login']);
}

// ✅ Check permissions in component
if (this.authService.hasPermission('articles:delete')) {
  // Show delete button
}

// ✅ Protect routes with guards
export const routes = [
  {
    path: 'admin',
    component: AdminComponent,
    canActivate: [AdminGuard], // Checks authorization
  },
];

// ✅ Implement permission-based access
@Injectable()
export class AdminGuard implements CanActivate {
  constructor(
    private auth: AuthService,
    private router: Router,
  ) {}

  canActivate(): boolean {
    if (this.auth.hasRole('admin')) {
      return true;
    }
    this.router.navigate(['/unauthorized']);
    return false;
  }
}

DO NOT open public issues for security vulnerabilities!

Report privately:

1. Email: security@example.com
2. Subject: [SECURITY] Vulnerability in Front-End App
3. Include:
   • Vulnerability description
   • Severity (Critical/High/Medium/Low)
   • Affected component/file
   • Steps to reproduce
   • Your name and contact info (optional)

Response Timeline:

• Initial Response: Within 48 hours
• Fix Development: Depends on severity
• Release: ASAP after fix verification

After fixing security issues:

1. Update SECURITY.md
2. Release patch version (e.g., 1.0.1)
3. Notify users of update
4. Document mitigation for unpatched systems

• No hardcoded credentials
• User input validated and sanitized
• API responses validated against schema
• Errors don't leak sensitive information
• HTTPS used for all API calls
• Auth tokens in sessionStorage (not localStorage)
• Unused dependencies removed
• Dependencies scanned for vulnerabilities
• Third-party libraries audited
• NoSQL injection prevented (if applicable)
• XXE attacks prevented
• CSRF tokens implemented
• XSS protection enabled
• SQL injection prevented (backend)
• Rate limiting implemented

• No new hardcoded secrets
• Input validation present
• Error messages safe
• Dependencies updated safely
• Security libraries used correctly
• No dangerous functions (eval, innerHTML, etc)
• Cryptography implemented correctly

• Environment variables configured
• Secrets manager integrated
• HTTPS certificate valid
• Security headers set (CSP, X-Frame-Options, etc)
• CORS properly configured
• Rate limiting enabled
• WAF rules configured
• Logging/monitoring enabled
• Incident response plan ready

• Monitor error logs for exploits
• Monitor dependency vulnerabilities
• Review access logs periodically
• Update security policies quarterly
• Security training for team
• Penetration testing scheduled (annually)

• OWASP Top 10
• OWASP Authentication Cheat Sheet
• Angular Security Guide
• TypeScript Security

1. Least Privilege: Users only get access they need
2. Defense in Depth: Multiple layers of security
3. Fail Securely: Errors don't expose vulnerabilities
4. Security by Default: Secure settings enabled by default
5. Code Review: Security-focused peer reviews

Last Updated: April 2026
Next Review: April 2026 (Quarterly)