Web Application Security Checklist for Small Businesses

Why small businesses are targets

Attackers do not only go after large companies. Automated tools scan the internet constantly for outdated software, weak passwords and misconfigured servers, and small businesses are often easier to compromise. A breach can mean stolen customer data, a defaced site, ransomware or fraudulent payments, and it damages trust that took years to build. The good news is that most attacks exploit well-known weaknesses that can be closed with routine practices.

Authentication and access

Most breaches begin with credentials. Protect them carefully:

• Store passwords only as salted hashes using a modern algorithm such as bcrypt or Argon2, never in plain text.
• Enforce sensible password rules and block commonly used passwords.
• Offer multi-factor authentication, and require it for administrators.
• Lock or slow down accounts after repeated failed logins.
• Give each user only the permissions their role needs, and review them regularly.

Protect data in transit and at rest

Serve the entire site over HTTPS and redirect all HTTP requests. Use secure, HttpOnly cookies for sessions. Encrypt sensitive fields in the database where appropriate, and never keep secrets such as API keys, database passwords or payment keys in the code repository or in front-end code. Store them in environment variables or a secrets manager.

Defend against the common attacks

Most web vulnerabilities fall into a few categories, and good frameworks help, but only if they are used correctly.

• SQL injection: use parameterised queries or an ORM, never string-built SQL.
• Cross-site scripting (XSS): escape output and use a content security policy.
• Cross-site request forgery (CSRF): use anti-forgery tokens on state-changing requests.
• Broken access control: check permissions on the server for every request, not just in the interface.
• File uploads: validate type and size, store them outside the web root and scan where possible.

Handle payments safely

When you take payments through gateways such as Paystack or Flutterwave, the card details should never touch your server. Always confirm a transaction on the server by calling the gateway verification endpoint with your secret key, and compare the amount and currency to what you expected. Never trust a success message coming from the browser alone, because it can be forged.

Keep everything updated

Out-of-date frameworks, plugins and server software are the most common way in. Subscribe to security advisories for the tools you use, apply updates promptly, remove plugins you do not use and run dependency audits as part of your build process.

Backups, logging and monitoring

Take automatic backups, store copies away from the main server and test restoring them. Keep logs of logins, errors and administrative actions, and set alerts for unusual activity such as many failed logins or sudden traffic spikes. Without logs you cannot tell what happened after an incident.

Make it routine

Security is a practice, not a one-off project. Schedule a regular review of user accounts, permissions, updates and backups, and have your application tested by someone independent from time to time.