Hey there!
Securing Node.js applications is crucial these days, as Node‘s popularity also makes it a bigger target. From my experience as a developer and analyst, I wanted to share the tools I think are most valuable for locking down your Node.js apps and keeping them safe.
While nothing can make an app 100% secure, adhering to security best practices and leveraging the right tools can help avoid many vulnerabilities. Let‘s first go over some tips for building secure Node.js apps:
Node.js Security Best Practices
- Log and monitor app activity – Detect attacks and anomalous behavior
- Avoid blocking the event loop – Prevent performance issues
- Use flat promise chains – Nesting often leads to errors
- Strong authentication – Protect account access and prevent brute force
- Handle errors properly – Don‘t reveal unnecessary info
- Anti-CSRF tokens – Prevent cross-site request forgery
- Only send required data – Reduce exposure of sensitive info
- Secure cookies and sessions – Set flags like HttpOnly and Secure
- Limit request size – Help guard against DDoS
- Custom npm settings – Use a
.npmrc
file for tighter access - Non-default passwords – Change defaults for databases, caches, etc.
- Implement granular access control – Least privilege access
- Keep dependencies updated – Get security fixes and patches
- Set security headers – Protect against common web attacks
- Avoid dangerous functions – Prioritize stability over convenience
- Use strict mode – More safety nets for mistakes
Now let‘s look at some excellent tools to further lock down Node.js apps. I‘ll share tools I‘ve used personally and recommend based on features, support, and overall value.
Snyk – Continuous Vulnerability Monitoring
Snyk is one of my go-to recommendations for Node.js security. It scans application dependencies to detect vulnerabilities, provides continuous monitoring for new threats, and even automatically fixes vulnerable packages.
The main value propositions:
- Vulnerability scanning – Identify risks like arbitrary code execution, DoS, injection attacks
- Real-time monitoring – Get alerts when new issues arise
- Auto-remediation – Fix vulnerable dependencies and outdated packages
- Alerting – Be notified when new threats impact your apps
- Collaboration – Share and discuss findings with your team
Snyk maintains a comprehensive vulnerability DB that covers Node.js, Ruby, Python, .NET, Java, Go, and more.
It also integrates into your workflows – GitHub, GitLab, Bitbucket, CI/CD systems, IDEs, and more. This allows seamless scanning throughout the development lifecycle.
The 2022 Open Source Security and Risk Analysis report by Snyk found:
- 83% of applications contained open source vulnerabilities
- The average app had 178 vulnerabilities
- 77% of vulnerabilities allowed remote code execution or denial of service
So continuous scanning and monitoring with Snyk can help uncover the risks in your code before they lead to a breach.
Jscrambler – Client-Side JavaScript Protection
Jscrambler takes a unique approach – instead of just scanning for risks, it transforms and obfuscates JavaScript code to make it self-protecting and tamper-proof.
Some traditional web security tactics like input validation, rate limiting, WAFs, etc. aim to prevent attacks on the server side.
But Jscrambler focuses on client-side protection – making the JS impossible to reverse engineer or modify. It does this through code transformations like:
- Encryption and hashing algorithms to obfuscate code and data
- Splitting code logic across randomized self-destroying strings
- Browser-fingerprinting anchors to detect tampering or unauthorized environments
- Polymorphism and constant shuffling to create dynamic, stateful logic
- Disabling browser debugger tools and error logging
This can prevent client-side attacks like:
- Tampering and alteration of JavaScript
- Scraping and theft of sensitive data
- Injection of malicious code into the page
- Man-in-the-browser attacks
- Account takeover through stolen tokens
Jscrambler integrates with Node.js servers through an API – you make a request to obfuscate code, and it returns secured JavaScript back.
They claim a 96% reduction in key leaks from protected apps, which is excellent considering more subtle client-side attacks that can evade server defenses.
So Jscrambler adds that client-side layer alongside robust server security.
Cloudflare WAF – Fast CDN and Edge Security
A WAF (web application firewall) inspects traffic and blocks attacks targeting your apps.
Cloudflare WAF places this inspection at the network edge, before requests even reach your origin servers.
This provides security with other benefits:
Faster performance – Static content is cached at the edge, closer to users
DDoS protection – Cloudflare absorbs and filters large volume attacks
One central policy – Rules apply across the global network edge
No hardware or software required – It‘s purely a network service
There are three types of managed rules:
- OWASP Top 10 – Common flaws like XSS, injection, broken auth
- Cloudflare Specials – Advanced protections they customize
- Custom Rules – You define specific rules
Pricing is based on domain count and advanced features:
- Free plan – Up to 20 domains with core WAF capabilities
- Pro plan – $20/month for unlimited domains, advanced WAF
- Business plan – $200/month with extra DDoS mitigation
So Cloudflare WAF brings speed, scalability, ease of use, and robust protection without needing to mess with firewall hardware.
Helmet – Quick Security Headers
Helmet is a simple Node.js middleware for setting security-related HTTP response headers.
Unlike full-featured WAFs, Helmet just makes it easy to implement common header-based protections:
- Content-Security-Policy – Allow/block resources like JS, CSS, images
- Referrer-Policy – Whether to pass referrer information
- X-Frame-Options – Clickjacking protection
- X-XSS-Protection – Cross-site scripting filter
- HTTP Public Key Pinning – Prevent man-in-the-middle attacks
It has a modular design where you only enable the protections you want:
// Import and enable specific middlewares
const helmet = require(‘helmet‘)
app.use(helmet.contentSecurityPolicy())
app.use(helmet.referrerPolicy())
Helmet is a nice complement to other defenses – quick to implement and addresses common vulnerabilities.
N|Solid Node.js Platform
N|Solid from NodeSource offers an enhanced Node.js runtime that bakes in security capabilities.
It instruments the Node.js core to detect suspicious activity at runtime, and lets you define security policies that get enforced during execution.
Some key features:
Real-time detection – Identify injection attacks, data leaks, suspicious actions
Instrumentation – Monitor memory, network, file system, and more
Security policies – Block activity that violates rules
Incident monitoring – Centralized dashboard of threats
Vulnerability scans – CVE monitoring and integration with tools like Snyk
N|Solid essentially extends Node.js to embed runtime monitoring and protection. It‘s deployed similarly – you install the N|Solid agent and run apps on it instead of stock Node.js.
For organizations that rely heavily on Node.js, N|Solid is a robust option that embeds security deeply into the runtime.
Rate Limiting Middleware
Rate limiting protects applications by restricting the number of requests allowed from a given IP address or user account. This helps prevent brute force login attacks, DDoS floods, web scraping abuse, and more.
There are several good rate limiting middleware options for Express apps, like express-rate-limit.
Basic usage:
const rateLimit = require("express-rate-limit");
// Limit each IP to 100 requests per windowMs
app.use(
rateLimit({
windowMs: 60 * 1000, // 1 minute
max: 100
})
);
More advanced capabilities like storing rate limit counters in Redis or memcache allow limiting across distributed apps.
Key scenarios where rate limiting helps:
- Allow only 10 login attempts per minute
- Stop bots scraping content by limiting page views
- Prevent API key abuse by limiting requests per key
- Block an IP after exceeding thresholds for errors or bandwidth
Rate limiting is an essential tool for enforcing usage policies and preventing abuse.
RASP – Runtime App Self-Protection
RASP (Runtime Application Self-Protection) is an emerging security technology – unlike traditional scanners, RASP instruments apps to detect and block attacks in real-time.
Vendors like Imperva embed sensors into apps that analyze execution flows and data flows across features like:
- User input and outputs
- File I/O
- Network activity
- Application memory
- Config and environmental interactions
- Access control
These sensors detect attack patterns and anomalies – things like injection attacks, XSS, insecure configs, DDoS, etc. Policies can be defined to take actions like logging, alerting, terminating requests, or blocking users.
RASP provides runtime insight hard to achieve with static or dynamic scanners. For security-critical apps, RASP is worth evaluating.
DOMPurify – Blazing Fast HTML Sanitizer
Cross-site scripting (XSS) is an unfortunately common threat – hackers inject malicious JS into pages to steal data or perform actions as users.
DOMPurify is a superb open source HTML/SVG/MathML sanitizer that defeats XSS.
It works by stripping HTML of dangerous elements – things like <script>
, <object>
, unsafe URLs, etc.
Basic usage:
const createDOMPurify = require(‘dompurify‘);
const { JSDOM } = require(‘jsdom‘);
const window = new JSDOM(‘‘).window; // Need DOM for purify
const DOMPurify = createDOMPurify(window);
const clean = DOMPurify.sanitize(dirty);
DOMPurify is very fast – it uses highly optimized sanitization algorithms for blazing performance.
Sanitizing user-supplied HTML is a must, and DOMPurify makes it easy to implement robust XSS protection.
AppTrana Cloud WAF
Like Cloudflare, AppTrana provides a fully managed, cloud-based WAF.
Some standout aspects of AppTrana:
Smart CDN – Caches content at the edge while protecting origin infrastructure
Bot mitigation – Advanced techniques to filter malicious automated traffic
Managed detection and response – Security analysts monitor risks and tune policies
Web app scanning – Automated + manual assessment of vulnerabilities
DDoS protection – Absorb and filter volumetric attacks in the cloud
Compliance reporting – Produce reports showing compliance with standards
Global edges – Distribute policies worldwide for optimal performance
Their cloud delivery model allows scaling WAF capabilities quickly without hardware headaches. Like Cloudflare, AppTrana brings robust protection complemented by speed and reliability improvements.
The Right Tools = Peace of Mind
Well there‘s my take on some excellent options for securing Node.js web apps and APIs. The specific tools you choose depends on your environment and risk profile. But taking advantage of SAST, DAST, WAFs, RASP, and other protections can help you identify and remediate vulnerabilities before they turn into headlines!
Hopefully this guide gave you some ideas on advancing the security of your Node.js apps. Feel free to reach out if you have any other questions!