TL;DR

Most web application attacks exploit well-known vulnerabilities that cheap, automated tools can catch today. You do not need a $50,000 security consultant. A combination of free SAST (code scanning), DAST (running application scanning), API testing, and container scanning can find and fix OWASP Top 10 risks before attackers do. This article gives you a one-week plan, real tool names, and costs from $0 to $500 per month.​‌‌​​​​‌‍​‌‌‌​​​​‍​‌‌‌​​​​‍​​‌​‌‌​‌‍​‌‌‌​​‌‌‍​‌‌​​‌​‌‍​‌‌​​​‌‌‍​‌‌‌​‌​‌‍​‌‌‌​​‌​‍​‌‌​‌​​‌‍​‌‌‌​‌​​‍​‌‌‌‌​​‌‍​​‌​‌‌​‌‍​‌‌​‌​​‌‍​‌‌​‌‌‌​‍​​‌​‌‌​‌‍​‌‌​‌‌‌‌‍​‌‌​‌‌‌​‍​‌‌​​‌​‌‍​​‌​‌‌​‌‍​‌‌‌​‌‌‌‍​‌‌​​‌​‌‍​‌‌​​‌​‌‍​‌‌​‌​‌‌‍​​‌​‌‌​‌‍​‌‌‌​‌​​‍​‌‌​‌‌‌‌‍​‌‌​‌‌‌‌‍​‌‌​‌‌​​‍​‌‌‌​​‌‌‍​​‌​‌‌​‌‍​‌‌‌​​‌‌‍​‌‌​​​‌‌‍​‌‌​​​​‌‍​‌‌​‌‌‌​‍​‌‌‌​​‌‌

The Problem: Your Software Has the Same Old Holes

Every business runs software, custom or off-the-shelf. Attackers do not write zero-day exploits for most SMB targets. They run automated scanners looking for missing patches, exposed admin panels, SQL injection points, and broken authentication. The OWASP Top 10 has barely changed in a decade because developers keep making the same mistakes, and businesses skip scanning because it sounds expensive.

It is not. You can scan your web app, your APIs, and your containers this week for free or less than $500 per month. This post shows you exactly what to do and what tools to use.​‌‌​​​​‌‍​‌‌‌​​​​‍​‌‌‌​​​​‍​​‌​‌‌​‌‍​‌‌‌​​‌‌‍​‌‌​​‌​‌‍​‌‌​​​‌‌‍​‌‌‌​‌​‌‍​‌‌‌​​‌​‍​‌‌​‌​​‌‍​‌‌‌​‌​​‍​‌‌‌‌​​‌‍​​‌​‌‌​‌‍​‌‌​‌​​‌‍​‌‌​‌‌‌​‍​​‌​‌‌​‌‍​‌

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The One-Week AppSec Sprint

Day 1-2: SAST, Catch Vulnerabilities in Your Code

Static Application Security Testing (SAST) scans your source code before it runs. It finds injection flaws, hardcoded secrets, insecure deserialization, and other bugs from the OWASP Top 10 categories like Injection (A03:2021) and Cryptographic Failures (A02:2021).

What to use:

  • SonarQube Community Edition $0, self-hosted. Scans 35+ languages. Install on a $20 VPS or your build server. Integrates with GitHub, GitLab, Bitbucket. It catches code smells and security hotspots together, which saves time.
  • Snyk Code free tier for small teams (1 dev free, then $25/dev/month). It shows the data flow from user input to vulnerable function, making injection flaws obvious. The free tier covers SAST and open-source dependency scanning.

What to do:

  1. Install SonarQube Community on a Linux box (docker run sonarqube:community).
  2. Connect your main web app repository.
  3. Run the first scan. Do not fix all 1,000 issues. Sort by severity, fix Critical and Blocker items first.
  4. Put a sonar.qualitygate in your CI pipeline to block new critical issues.

Day 3-4: DAST, Hit Your Running App Like an Attacker

Dynamic Application Security Testing (DAST) scans your running application from the outside. It spiders your site, sends attack payloads, and reports what actually works. This covers Broken Access Control (A01:2021), Security Misconfiguration (A05:2021), and Cross-Site Scripting (A03:2025).

What to use:

  • OWASP ZAP $0, open-source. Desktop GUI or headless in CI. The full scan finds SQLi, XSS, path traversal, and misconfigurations in 30-90 minutes. Use the "Ajax Spider" for JavaScript-heavy apps.
  • Burp Suite Community Edition $0. Manual testing power tool, but the automated scanner is limited. Good for targeted checks on login pages and APIs.

What to do:

  1. Run ZAP Quick Start against your staging environment (never production on first scan).
  2. Fix all High and Critical alerts, especially anything with "SQL Injection" or "XSS".
  3. Set up ZAP Baseline Scan in your CI pipeline. It runs a passive scan on every deploy and fails the build if new high-confidence issues appear.
  4. Check your HTTP headers: curl -I https://yourapp.com. Missing Content-Security-Policy, X-Frame-Options, or X-Content-Type-Options? ZAP flags them. Add them.

Day 5: API Security, The Hidden Attack Surface

APIs are often less protected than the main web app. An exposed /api/v1/users that returns all user records because no authorization check exists is a Broken Access Control nightmare. The OWASP API Security Top 10 exists separately for this reason.

What to use:

  • Postman $0 for API testing. Combine with OWASP ZAP as a proxy: Postman sends requests through ZAP, which identifies vulnerable endpoints.
  • Postman collections define every endpoint. Run them against staging, then review ZAP alerts.

What to do:

  1. List every API endpoint your business exposes (internal and external).
  2. For each endpoint, verify authentication is required. If an endpoint returns data without a valid token, that is a critical finding.
  3. Check that /api/admin endpoints are not exposed to the internet. Use a simple curl test to confirm.
  4. Test rate limiting: send 100 requests in 10 seconds to a login endpoint. No throttle? That is a brute-force vulnerability.

Day 6: Container Scanning and Dependency Checks

If you use Docker containers, your base images are full of known vulnerabilities. Attackers scan Docker Hub for outdated images. Trivy checks your containers and your application dependencies.

What to use:

  • Trivy $0, open-source. Scan images, filesystems, and git repos. Run trivy image your-app:latest to see all CVEs.
  • Snyk Open Source (included in free tier). Checks your package.json, requirements.txt, pom.xml for known vulnerable libraries.

What to do:

  1. Scan your container images. Fix everything with CVSS 9.0+ first.
  2. Update your base image tag. python:3.11-slim not python:latest.
  3. Add Trivy to your CI: every image build fails if a critical CVE exists with a fix available.

The $0-$500/Month Tool Stack for SMBs

Tool Capability Cost
SonarQube Community SAST, code quality $0 (self-host)
OWASP ZAP DAST, automated scanning $0
Trivy Container, dependency, IaC scanning $0
Postman API design and testing $0 (basic)
Snyk Team SAST + SCA + container, unified $25/dev/month (free for 1 dev)
Burp Suite Pro Advanced DAST, manual testing $449/year
Semgrep OSS SAST with custom rules $0

Most SMBs can start at $0 and upgrade when the business outgrows free limits. Even the $500/month tier costs less than one incident response.

What NIST and CIS Recommend

NIST SP 800-218, the Secure Software Development Framework, says prepare the organization, protect the software, produce well-secured software, and respond to vulnerabilities. SAST and DAST are part of the "produce" and "protect" phases. CIS Controls v8 maps SAST to Control 16 (Application Software Security), specifically requiring static and dynamic code analysis for applications handling sensitive data.

These are not aspirational guidelines. If you handle customer data, payment card information, or health records, scanning is a baseline expectation from your cyber insurer and from regulators.

FAQ

What if I have no source code access (SaaS or vendor-built app)? You skip SAST. Run DAST with ZAP against the staging or production environment (with permission). Many vendors allow security scanning in their terms of service. The scan finds misconfigurations and injection points you can report for remediation.

Our budget is zero. Can we still do this? Yes. SonarQube Community, OWASP ZAP, Trivy, and Postman are all free and run on a spare Linux machine. The only cost is your time. Block out one week. The quick wins, missing security headers and exposed admin panels, take hours to find and fix.

How often should we scan? DAST weekly against staging, SAST on every code commit. A one-time scan is worse than no scan; it gives false confidence. Automate the scans or schedule them in your calendar like a recurring meeting.

Our developers will fight this. How do we make it stick? Start with low-noise tools. SonarQube's quality profile can be tuned so the first run only flags Critical severity. Developers see clean code wins, not 5,000 warnings. Put the tool in their existing workflow (GitHub PR comments), not in a separate portal they never open.

Conclusion

The attackers scanning your app right now are not genius hackers. They are running scripts that check for missing patches and open admin endpoints. Your defense is cheap, automated, and achievable in a week. Start with SonarQube and ZAP tomorrow, scan your APIs on Wednesday, lock down your containers on Thursday, and automate everything on Friday.

Stop guessing whether your web app is secure. Scan it. Fix the critical findings. Then scan it again.

Visit consult.lil.business for a free 30-minute cybersecurity assessment. We will walk through your web application stack, run an initial ZAP scan, and give you a prioritized remediation plan. No pitch, no upsell, just actionable security advice.

References

  1. OWASP Top 10:2025
  2. NIST SP 800-218 Secure Software Development Framework
  3. CIS Controls v8 - Control 16: Application Software Security
  4. Australian Cyber Security Centre (ACSC) - Essential Eight
  5. Snyk vs SonarQube Comparison (2026)
  6. OWASP ZAP - Getting Started
  7. Trivy - Container Vulnerability Scanner

5 Free Security Guards for Your Business Computers (No IT Degree Required)

ELI10 version — five tools, zero cost, explained plainly.

TL;DR

  • Bitwarden: a free safe that stores all your passwords so you never reuse them
  • CrowdSec: a community neighbourhood watch for your server — blocks known bad guys automatically
  • Wazuh: a free security camera system that watches everything and alerts you when something's wrong
  • Tailscale: a private tunnel between your devices that replaces your VPN — simpler and safer
  • ClamAV: a free guard dog that sniffs out viruses on the computers your regular antivirus ignores

The security industry loves to sell you expensive things. Annual subscriptions, enterprise platforms, managed service contracts.

Here's the secret: some of the best security tools in the world are completely free. Not free trials — actually free — used by hospitals, government agencies, and banks because they're built by the security community and maintained openly.

Let me introduce you to five of them.

1. Bitwarden — The Safe for Your Passwords

The problem it solves: According to the Verizon 2024 Data Breach Investigations Report, compromised credentials are the #1 initial access vector in data breaches [1]. Most credential theft works because people reuse the same password everywhere — so when one site leaks its passwords, attackers try that password on your email, bank, and business software.

What Bitwarden does: It's like a secure safe that stores a unique, random password for every website you use. You only remember one master password — Bitwarden handles the 50 unique ones. You never reuse a password again.

Why it's free: Bitwarden is open-source — the code is public and auditable. It passed an independent security audit by Cure53 with no critical vulnerabilities found [2].

How hard is it to set up: 30 minutes. Go to bitwarden.com, make an account, install the browser extension, import your passwords.

2. CrowdSec — The Neighbourhood Watch for Your Server

The problem it solves: Every day, automated programs scan the internet looking for vulnerable servers. CISA's Known Exploited Vulnerabilities catalogue shows that automated exploitation of internet-facing services is a top initial access technique [3].

What CrowdSec does: It watches who's knocking on your server's door. When it spots someone trying too many passwords in a row, or scanning for vulnerabilities, it automatically bans their address. It shares that intelligence with thousands of other businesses running CrowdSec — so when one business bans an attacker, everyone's list gets updated. CrowdSec has blocked over 100 billion malicious requests globally [4].

How hard is it to set up: Your IT person can set it up in under an hour on a Linux server.

3. Wazuh — The Security Camera System

The problem it solves: According to IBM's 2024 Cost of a Data Breach Report, the average breach goes undetected for 194 days [5]. Most businesses have no idea when something suspicious happens because they have no visibility tools.

What Wazuh does: It's like security cameras throughout your building, but for computers. It watches for unusual activity — files being changed, accounts behaving strangely, known attack patterns — and alerts you. The Australian Cyber Security Centre lists monitoring and logging as a critical control in its Essential Eight framework [6]. Wazuh delivers that at $0.

How hard is it to set up: This one needs your IT person or a specialist like lilMONSTER to deploy properly. But once running, it watches automatically.

4. Tailscale — The Private Tunnel (Better Than a VPN)

The problem it solves: Traditional VPNs have become major attack targets. CISA issued an Emergency Directive in January 2024 requiring agencies to immediately address critical vulnerabilities in Ivanti VPN products after active exploitation [7]. Tailscale's architecture eliminates the central VPN concentrator that attackers target.

What Tailscale does: It creates a private, encrypted tunnel between your devices — but instead of connecting you to the whole network, it connects you to specific systems you need. It uses your existing Google or Microsoft login to verify who you are — no new passwords to manage.

How hard is it to set up: Genuinely the easiest VPN replacement you'll use. Install the app on each device, log in with your Google account, done. Free for most small teams [8].

5. ClamAV — The Guard Dog That Checks Everything Else

The problem it solves: Most businesses run antivirus on Windows computers but leave Linux servers and email servers completely unmonitored. Those unmonitored systems can spread malware to every Windows machine that touches them.

What ClamAV does: It's an antivirus engine maintained by Cisco Talos — one of the world's largest commercial threat intelligence organisations [9] — that runs on Linux, Mac, and Windows servers. It's particularly good for email scanning, checking every attachment before it reaches your inbox.

How hard is it to set up: A few minutes on a Linux server: apt install clamav. Schedule regular scans with a single cron line.

The Honest Truth

These tools are free. The expertise to set them up and use them well has value. Installing Wazuh is one thing — understanding what it's alerting you to at 11pm is another. That's what lilMONSTER does for small businesses: deploy these tools properly, monitor what they find, and act on it.

Your Action Items

  • Set up Bitwarden today — bitwarden.com — 30 minutes
  • Ask your IT person about CrowdSec for your servers — crowdsec.net
  • Look into Tailscale as your VPN replacement — tailscale.com
  • Book a free consult with lilMONSTER to get Wazuh and ClamAV deployed properly

FAQ

Are these tools really free? Yes. Bitwarden (free individual tier, $3/user/month for business), CrowdSec (free), Wazuh (free open-source), Tailscale (free for up to 3 users/100 devices [8]), and ClamAV (always free [9]) are all genuinely free at small-team scale.

Do I need an IT person to set these up? Bitwarden and Tailscale can be set up without technical expertise. CrowdSec, Wazuh, and ClamAV benefit from server administration knowledge — or lilMONSTER can deploy them for you.

Can these replace paid security tools? For most small businesses, these five tools cover the most important attack vectors at zero cost. They deliver dramatically more protection than most SMBs currently have. See the full technical post for a detailed breakdown [link to full version].

References

[1] Verizon, "2024 Data Breach Investigations Report," Verizon Business, 2024. [Online]. Available: https://www.verizon.com/business/resources/reports/dbir/

[2] Cure53, "Bitwarden Cryptographic Analysis — Final Report," Cure53 Security Audit, 2022. [Online]. Available: https://bitwarden.com/help/is-bitwarden-audited/

[3] Cybersecurity and Infrastructure Security Agency, "CISA Known Exploited Vulnerabilities Catalog," CISA, 2024. [Online]. Available: https://www.cisa.gov/known-exploited-vulnerabilities-catalog

[4] CrowdSec SAS, "CrowdSec — Collaborative Security Platform," CrowdSec, 2024. [Online]. Available: https://www.crowdsec.net/

[5] IBM Security, "Cost of a Data Breach Report 2024," IBM Research, 2024. [Online]. Available: https://www.ibm.com/reports/data-breach

[6] Australian Signals Directorate, "Essential Eight Maturity Model," Australian Cyber Security Centre, Nov. 2024. [Online]. Available: https://www.cyber.gov.au/resources-business-and-government/essential-cyber-security/essential-eight/essential-eight-maturity-model

[7] Cybersecurity and Infrastructure Security Agency, "Emergency Directive ED-24-01: Mitigate Ivanti Connect Secure and Ivanti Policy Secure Vulnerabilities," CISA, Jan. 2024. [Online]. Available: https://www.cisa.gov/news-events/directives/ed-24-01

[8] Tailscale Inc., "Tailscale — Identity-Based Networking," Tailscale Documentation, 2024. [Online]. Available: https://tailscale.com/

[9] Cisco Talos Intelligence Group, "ClamAV Open Source Antivirus," Cisco Talos, 2024. [Online]. Available: https://www.clamav.net/

Want these tools deployed and actually working — not just installed? Book a free consultation with lilMONSTER. We set up, configure, and monitor open-source security stacks for small businesses.

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