On November 18, 2025, Cloudflare experienced a massive outage that affected millions of websites worldwide.
This incident highlights the potential risks of relying on cloud-based Web Application Firewalls (WAFs).
1. The Root Cause of the Outage
According to Cloudflare's post-mortem, the outage was triggered by abnormal spikes in feature files used by Bot Management:
- Database permission changes caused duplicate entries in the feature files.
- These abnormal files were propagated globally, overloading key services.
- Core proxy services crashed, rendering client websites inaccessible.
Even minor misconfigurations or unusual traffic patterns can cause cloud WAFs to fail, leaving websites completely offline.
2. Hidden Risks of Cloud WAF
The Cloudflare outage exposed several fundamental risks for businesses relying on cloud WAFs:
Uncontrollable dependency: Websites are fully dependent on Cloudflare nodes and Bot Management. Any anomaly in the cloud infrastructure directly affects site availability.
Delayed response: When problems occur, businesses cannot fix them immediately and must wait for Cloudflare to resolve the issue.
Complex configuration: Bot Management rules and feature files are abstract and difficult for typical administrators to debug.
Global impact: A single configuration or data error in the cloud can affect global traffic, causing extensive downtime.
These issues are especially critical for finance, e-commerce, SaaS, and other services where uptime is crucial.
3. Self-hosted Alternative to CloudFlare
SafeLine, a self-hosted WAF, provides significant benefits in mitigating bot attacks and maintaining business continuity:
Local deployment and full control: All rules, logs, and traffic analysis are on-premises, without reliance on third-party cloud infrastructure.
Accurate threat detection: Anti-Bot Challenge can intelligently identify malicious traffic while minimizing impact on legitimate users.
Real-time debugging and visibility: Administrators can instantly view request logs, blocked events, and IP information.
Flexible rules: Each application can be configured independently with HTTP Flood protection, CAPTCHA, access control, and more.
4. The Value of Self-Hosted WAFs
Independence: Operations are unaffected by cloud service failures.
Data control: All logs and audit trails remain within the enterprise network, ensuring privacy and compliance.
Cost predictability: No per-traffic fees or unexpected global load charges.
Rapid response: Businesses can adjust rules or block traffic immediately without waiting for third-party support.
5. Conclusion
The Cloudflare outage serves as a warning: relying solely on cloud WAFs is not foolproof. For enterprises prioritizing business continuity, data privacy, and traffic control, self-hosted WAFs like SafeLine provide:
- Complete visibility and control
- Reliable Anti-Bot Challenge
- Rapid threat response
Choosing a self-hosted solution allows businesses to defend against attacks while maintaining operational stability—something cloud WAFs alone cannot guarantee.
SafeLine is a self-hosted Web Application Firewall (WAF) with over 400,000 installations globally. It offers simple deployment, accurate threat detection, and advanced anti-bot protections.
SafeLine Website: https://ly.safepoint.cloud/ShZAy9x
Live Demo: https://demo.waf.chaitin.com:9443/statistics
Discord: https://discord.gg/dy3JT7dkmY
Doc: https://docs.waf.chaitin.com/en/home
Github: https://github.com/chaitin/SafeLine
Top comments (1)
With the Speed of AI Rise, I think the cyber security and network security must also raise concerns.