We all know that web applications bring convenience to users across various businesses, including e-commerce, SaaS, fintech, and healthcare. For the same reason, they are also prime targets for hackers. Unfortunately, many breaches happen not because attackers are geniuses, but because the app’s security foundations are weak due to missed security check such as web app penetration testing.
In this article, we will discuss the most common mistakes that make a web app an easy target.
1. Skipping Regular Web App Penetration Testing
A web app that isn’t tested regularly is like a house with unlocked doors. Cyber threats evolve quickly, and vulnerabilities that didn’t exist last month may appear after a code update, plugin installation, or server configuration change.
- Without Vulnerability Assessment and Penetration Testing (VAPT), hidden weaknesses remain unnoticed.
- Testing should include both manual and automated methods for thorough coverage.
Tip: Make security testing part of your development lifecycle, not just a one-time event. You can choose a third-party vendor like Peneto Labs to conduct Vulnerability Assessment and Penetration Testing (VAPT).
2. Weak Authentication and Session Management
Many breaches happen because attackers can easily guess or steal login credentials. Weak authentication systems give them the key to your web app.
Common issues include:
- No multi-factor authentication (MFA)
- Reusing default passwords
- Session IDs that are predictable
- No session timeouts
Fix:
- Enable MFA for all admin and sensitive accounts.
- Rotate session tokens regularly.
- Enforce strong password policies.
3. Poor Input Validation
If your app accepts user inputs—whether through forms, search bars, or APIs—without validation, you’re inviting trouble. This is how attacks like SQL Injection or Cross-Site Scripting (XSS) happen.
Examples:
- A login form that accepts SQL code as input.
- A comment box that allows malicious JavaScript to run.
Fix:
- Validate and sanitise inputs on the server side.
- Never rely solely on client-side validation.
4. Storing Sensitive Data Without Proper Encryption
Storing passwords, payment details, or customer data in plain text is one of the biggest mistakes. If attackers gain access to your database, they’ll have everything in readable form.
Best practices:
- Use strong encryption algorithms (AES-256, SHA-256).
- Store passwords with salted hashing.
- Encrypt data in transit with HTTPS/TLS.
5. Outdated Frameworks, Libraries, and Plugins
Hackers actively scan for known vulnerabilities in popular frameworks and plugins. If you’re using outdated versions, you’re practically leaving the door open.
Examples:
- Old WordPress plugins with public exploit codes.
- Unsupported JavaScript libraries still running in production.
Solution:
- Keep all software updated.
- Remove unused dependencies.
6. Misconfigured Cloud or Server Settings
Even the most secure code can’t save you if your infrastructure is misconfigured. A single open port or public storage bucket can leak sensitive data.
Common mistakes:
- Exposed admin panels without IP restrictions.
- Publicly accessible AWS S3 buckets.
- Weak firewall rules.
Fix:
- Regularly audit cloud permissions and server configurations.
- Implement the principle of least privilege for all accounts.
7. Poor Error Handling
Error messages are for developers—not hackers. Yet many web apps display detailed system errors that reveal too much information.
Example:
A failed login error that shows the exact SQL query used, giving attackers insight into your database structure.
Best practice:
- Show generic error messages to users.
- Log detailed errors internally for troubleshooting.
8. Ignoring Third-Party Integrations
Many apps rely on APIs, payment gateways, or analytics tools. If these integrations are insecure, they can become an easy entry point for attackers.
Steps to secure them:
- Use API keys and authentication tokens.
- Limit API access to specific IP addresses.
- Monitor third-party services for vulnerabilities.
9. Lack of Access Control
Giving users more access than they need increases the damage in case of a breach. For example, a junior employee shouldn’t have database admin rights.
Fix:
- Apply role-based access control (RBAC).
- Review and update permissions regularly.
10. No Incident Response Plan
Even with the best security measures, incidents can happen. Without a response plan, you’ll waste valuable time figuring out what to do after a breach.
What to include in a plan:
- How to isolate affected systems.
- Who to notify internally and externally.
- Steps for reporting to CERT-In (mandatory within 6 hours for certain incidents).
11. Not Monitoring Application Activity
If you’re not watching what’s happening inside your web app, you might miss early warning signs of an attack. Many breaches go unnoticed for weeks simply because no one was monitoring logs or suspicious activities.
Fix:
- Set up real-time alerts for unusual login attempts, traffic spikes, or data exports.
- Review logs regularly and keep them secured from tampering.
12. Lack of Security in Development Practices
Security isn’t something you “add later.” If your development process doesn’t include secure coding practices from the start, vulnerabilities will slip through.
Best practices:
- Train developers on OWASP Top 10 vulnerabilities.
- Conduct code reviews with a security checklist.
- Use static and dynamic application security testing (SAST/DAST) during development.
Key Takeaways
Cybersecurity isn’t just about having the right tools—it’s about avoiding these basic yet critical mistakes that leave your web app vulnerable.
- Test your web app regularly.
- Keep everything updated.
- Validate inputs and secure data.
- Limit access to what’s necessary.
Remember, hackers often look for the easiest target, not the toughest one. By fixing these common mistakes, you make your web app a much harder target.
If you want help in securing your web applications, our team of expert cybersecurity penetration testers offers manual and automated VAPT, compliance-ready reports, and Safe-to-Host certification support.
Peneto Labs has been empanelled by CERT-In to conduct information security auditing services.
At Peneto Labs, we believe in following the cybersecurity laws and the law of the land. Connect to us now for a FREE consultation and save your web application from a potential braech. Stay secure, Stay compliant!