CC attacks are no longer limited to websites with obvious login pages or forms.
For many API-first SaaS companies, CC attacks arrive disguised as normal API calls — valid endpoints, valid parameters, valid authentication — yet still capable of exhausting backend resources.
This is a real-world user case showing how a mid-size SaaS team stopped recurring CC attacks and automated abuse by switching from a rule-based WAF to SafeLine’s semantic analysis WAF.
The Company Profile (Anonymized)
- Business type: B2B SaaS platform
- Architecture: API-first, REST + JSON
- Customers: SMEs and enterprise integrations
- Team size: < 20 engineers
- Security team: none (DevOps handled security)
The platform exposed multiple public APIs for data queries, reporting, and integrations. These APIs became the primary target.
The Attack Pattern They Couldn’t Explain
The team noticed recurring incidents with the following characteristics:
- CPU spikes on application servers
- Database query latency increasing sharply
- No abnormal bandwidth usage
- No obvious authentication failures
Traffic analysis showed:
- Requests coming from rotating IPs
- Valid API tokens being reused
- Normal request rates per IP
- Complex query parameters triggering expensive backend logic
This was classic CC behavior at the application layer, optimized to stay below traditional thresholds.
Why Existing Protections Failed
Rate Limiting Was Too Crude
Rate limits were already in place:
- Per-IP limits were bypassed with proxies
- Per-token limits broke legitimate enterprise integrations
- Tight limits caused customer complaints
Regex-Based WAF Rules Didn’t Understand APIs
The legacy WAF relied on keyword rules such as:
(select|union|sleep)\s+
Problems quickly emerged:
- JSON payloads triggered false positives
- Obfuscated attacks bypassed detection
- Engineers spent hours tuning rules after every incident
The team realized they were filtering strings, not understanding behavior.
The Shift to Semantic Analysis
Instead of trying to predict every possible payload pattern, the team adopted SafeLine WAF, focusing on what the request actually means, not how it looks.
SafeLine was deployed in front of both:
- Public web endpoints
- API gateways
No application code changes were required.
How SafeLine Identified Malicious API Calls
SafeLine’s detection logic worked at a deeper level:
1. Full Payload Reconstruction
- Recursive decoding of JSON, URL encoding, Unicode, and escape sequences
2. Language-Aware Parsing
- SQL-like fragments inside parameters were parsed as SQL
- JavaScript-like structures were parsed as code, not text
3. Intent Evaluation
SafeLine differentiated between:
1 + 1 = 2
and
union select user,password from users where
Even when heavily obfuscated.
4. Behavioral Correlation
- Repeated high-cost queries
- Identical semantic intent across different payload shapes
- Automated request timing patterns
This allowed SafeLine to block CC attacks without touching legitimate integrations.
Immediate Results
After deployment:
- CC traffic dropped sharply within days
- Database load normalized
- No customer-reported false positives
- No emergency rule tuning
Engineers reported that, for the first time, security stopped competing with availability.
Why This Worked Better Than Traditional WAFs
Traditional WAFs rely on regular expressions, which belong to the weakest class of formal grammars.
SafeLine uses compiler-level parsing, aligned with how real programming languages work:
- SQL, JavaScript, HTML → context-free grammars
- Regex → cannot reliably model nested or structured logic
In short:
Attackers write programs. SafeLine understands programs.
A Broader Lesson for API Security
This case highlights a growing reality:
- APIs are the new primary attack surface
- CC attacks increasingly target business logic
- Signature-based defenses will always lag behind attackers
Semantic analysis allows defenders to detect malicious intent, not just suspicious text.
Final Takeaway
For this SaaS team, SafeLine WAF turned CC defense from a constant operational burden into a stable, automated capability.
Instead of reacting to every new bypass technique, they gained a system that adapts to how attacks are constructed — even when attackers change how payloads are written.
For modern API-driven platforms, this approach is quickly becoming essential.
About SafeLine WAF
SafeLine is a self-hosted Web Application Firewall powered by intelligent semantic analysis. It protects web applications and APIs from CC attacks, SQL injection, XSS, and malicious automation with high accuracy and minimal false positives.
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