One-click deployment to stop hackers! Discover SafeLine (雷池), a free Web Application Firewall with semantic analysis. Block SQL injection, XSS, CC attacks and more.
One-click deployment, hackers cannot get through!
In today's digital era, cybersecurity threats are everywhere, and Web applications in particular are prime targets for hackers. SQL injection, XSS cross-site scripting, CC attacks… behind these technical terms lie the day-to-night worries of countless website administrators. Today, I'd like to introduce a powerful and completely free Web Application Firewall — SafeLine (雷池), which may well be the ultimate security solution for your website.
🔍 What is SafeLine?
SafeLine is a simple-to-use yet highly effective Web Application Firewall (WAF) designed to protect web services from hacker attacks.
SafeLine works by filtering and monitoring HTTP traffic between Web applications and the internet, defending your services against SQL injection, XSS, code injection, command injection, CRLF injection, LDAP injection, XPath injection, RCE, XXE, SSRF, path traversal, backdoors, brute force, CC attacks, crawlers, and more.
Since its release, SafeLine has earned broad market recognition:
- 🌍 Over 300,000 installations worldwide
- 🏢 Protecting more than 1 million websites
- ⚡ Processing over 30 billion HTTP requests daily
🔧 How Does SafeLine Work? A Look at the Core Principle
SafeLine's design philosophy is highly intuitive — it integrates into your network architecture as a reverse proxy. Think of it as a smart security guard at your website's entrance: every access request must pass through its inspection and verification before reaching your web server.
SafeLine's core working principles:
- 📡 Traffic Interception: SafeLine sits between users and your web server, so all HTTP/HTTPS traffic must pass through it first
- 🔎 Malicious Request Detection: Uses intelligent semantic analysis to deeply understand the intent of each request, rather than relying solely on signature matching
- 🚫 Real-time Blocking: Once malicious behavior is detected, requests are immediately blocked to protect the backend web service
- ✅ Clean Traffic Forwarding: Only safe traffic is forwarded to your web server
This mechanism ensures that attack traffic is thoroughly filtered before it ever reaches your website, significantly reducing the security burden on your server.
✨ Feature Highlights: Why Choose SafeLine?
The SafeLine Community Edition offers a comprehensive suite of powerful security features that fully meet the protection needs of small to medium-sized websites:
🔒 Comprehensive Web Attack Protection
SafeLine effectively defends against a wide range of common web attacks, including but not limited to SQL injection, XSS cross-site scripting, and various other injection attacks. Unlike traditional WAFs that rely solely on rule matching, its unique semantic analysis engine identifies attacks by understanding the true intent of the code, making it significantly better at detecting unknown and variant attacks.
🚦 Intelligent Rate Limiting
To counter CC attacks and brute force attempts, SafeLine provides flexible rate limiting. You can set custom access frequency thresholds based on your business needs; when a specific IP exceeds the limit, it is automatically temporarily blocked.
🤖 Human-Machine Verification
SafeLine can intelligently distinguish real users from automated programs (such as malicious crawlers and scanners). When suspicious automated behavior is detected, it can trigger human-machine verification (e.g., CAPTCHA) while remaining virtually invisible to legitimate users.
🔑 Identity Authentication Protection
For admin panels or sensitive paths requiring extra protection, SafeLine allows you to configure identity authentication, effectively preventing unauthorized access. Visitors must enter the preset username and password to proceed to protected resources.
🛡️ Dynamic Protection Technology
This is an impressive feature — SafeLine can dynamically encrypt HTML and JavaScript code. Without altering the content or functionality of the page, the code appears in a random and unique form on every visit, making it extremely difficult for attackers to analyze and exploit.
📊 Real-World Performance: How Effective is SafeLine?
Multiple third-party tests and user reports show that SafeLine performs exceptionally well in real environments:
In a series of penetration tests, SafeLine successfully intercepted:
- 🗃️ SQL Injection Attacks: Including various obfuscated and encoded SQL injection payloads
- 📁 Malicious File Uploads: Real-time blocking when attempting to upload webshells or other malicious files
- 📂 Directory Traversal Attacks: Preventing attackers from accessing unauthorized files
- 🌐 CC Attacks: In stress tests, SafeLine successfully identified and blocked high-frequency requests
- 🔍 Scanner Probes: Common vulnerability scanning tools such as FFUF were effectively identified and blocked
Particularly impressive is SafeLine's accuracy. According to official data, SafeLine achieves 99.45% accuracy in balanced mode and 99.38% in strict mode — far higher than some commercial WAF products.
⚖️ SafeLine vs Other WAFs: Why Choose SafeLine?
Compared with other Web Application Firewalls, SafeLine has several notable advantages:
Comparison with CloudFlare
| Feature | SafeLine | CloudFlare |
|---|---|---|
| Deployment | 🏠 On-premise | ☁️ Cloud service |
| Cost | 💰 Completely free | 💸 Free tier limited, advanced features paid |
| Data Privacy | 🔐 Fully self-controlled | 📊 Passes through third-party servers |
| Protection Performance | 🎯 99.45% accuracy | 🎯 Basic protection |
| Semantic Analysis | ✅ Supported | ❌ Limited |
Comparison with Traditional WAFs
Compared to traditional rule-based WAFs, SafeLine's semantic analysis engine offers clear advantages. Traditional WAFs rely on databases of known attack signatures, while SafeLine understands the context and semantics of requests — providing much better detection against unknown and variant attacks.
💡 Practical Tips: Maximizing SafeLine's Protection
🎯 Fine-tune Rate Limiting
Set access frequency thresholds according to your website's characteristics. For API endpoints, stricter limits work well; for static resources, looser limits avoid false positives against legitimate users.
🤖 Make Smart Use of Human-Machine Verification
Enable human-machine verification on sensitive paths like admin panels and login pages to effectively prevent attacks from automated tools.
📝 Review Monitoring Logs Regularly
SafeLine provides detailed attack logs and statistics. Reviewing them regularly helps you understand the threat landscape your website faces and adjust your protection strategy accordingly.
🌐 Configure IP Blacklists and Whitelists
For clearly malicious or trusted IPs, use the IP blacklist/whitelist feature to achieve precise access control.
🔐 SSL Certificate Configuration
Configure SSL certificates for your website — SafeLine fully supports HTTPS traffic protection and allows you to upload and manage SSL certificates directly within the platform.
📥 Installation and Deployment Guide
SafeLine is remarkably easy to install and supports multiple deployment methods:
🖥️ System Requirements
- 💻 Operating System: Linux
- ⚙️ CPU Architecture: x86_64 or arm64
- 🐳 Software Dependencies: Docker 20.10.14+ and Docker Compose 2.0.0+
- 💾 Resource Requirements: Minimum 1 CPU core / 1 GB RAM / 5 GB disk
🚀 Quick Installation
SafeLine provides a one-click installation script — just run the following command:
`bash -c "$(curl -fsSLk https://waf-ce.chaitin.cn/release/latest/setup.sh)"`During installation, the script will prompt you to set the installation directory, which defaults to /data/safeline.
👨💻 Manual Installation
For users familiar with Docker, manual installation is also available:
`mkdir -p safeline && cd safeline
curl -fLsS https://waf-ce.chaitin.cn/release/latest/compose.yaml -o compose.yaml
docker compose up -d`⚙️ Initial Configuration
- 🖥️ After installation, visit
https://your-server-IP:9443to access the management interface - 🔐 First login requires binding TOTP (Time-based One-Time Password) authentication — you can scan the QR code using apps like Google Authenticator or FreeOTP
- 🏠 After logging in, add the website you want to protect under "Protected Sites"
- 🔗 Configure the upstream server address (your website's actual address)
- 🛠️ Adjust protection policies as needed
🌐 Site Configuration Example
Suppose your website runs on the same server at port 8080; the upstream server should be configured as: http://127.0.0.1:8080
If your website uses HTTPS, remember to upload the SSL certificate to SafeLine.
🎉 Conclusion
As a free, efficient, and easy-to-use Web Application Firewall, SafeLine is undoubtedly a powerful security tool for website administrators. Whether you run a personal blog, a corporate website, or an e-commerce platform, you can benefit from SafeLine's protection.
Its semantic analysis technology delivers intelligent protection, the simple deployment lowers the barrier to entry, the comprehensive feature set covers most web threats, and its completely free nature makes it an ideal choice for budget-conscious users.
Cybersecurity shouldn't be a luxury. Now, deploy SafeLine WAF for your website and make hackers truly think twice before crossing the line!
Note: If you encounter any issues during installation or use, please visit the SafeLine official documentation or the project repository for help.
Note: This is the English translation of the original Chinese version.