Intermediate LevelWeb Security & Cyber Defense
What is a Web Application Firewall (WAF) and how does it filter malicious HTTP traffic?
❓ Interview Prompt: Explain Web Application Firewall (WAF), Layer 7 inspection, signature matching, anomaly scoring, ModSecurity, and AWS WAF rule groups.
A Web Application Firewall (WAF) operates at OSI Layer 7, inspecting incoming HTTP request payloads to block cyber attacks before they reach backend application servers:
WAF Capabilities:
•
Signature Matching: Detects known attack patterns (e.g. '<script>', '' OR 1=1', '../etc/passwd').
•
Rate Limiting & Bot Control: Blocks automated bad bot user-agents and IP request bursts.
•
OWASP Managed Rules: Protects against common web vulnerabilities out of the box.
Code Implementation Example
json
// AWS WAF Custom Managed Rule Group Configuration
{
"Name": "AWSManagedRulesCommonRuleSet",
"Priority": 1,
"Statement": {
"ManagedRuleGroupStatement": {
"VendorName": "AWS",
"Name": "AWSManagedRulesCommonRuleSet"
}
},
"OverrideAction": { "None": {} }
}💡AWS WAF Managed Rule Group configuration JSON.
🎯 Interview Key Takeaway
WAFs inspect Layer 7 HTTP traffic to block XSS, SQLi, and bot attacks before they hit backend application code.
#WAF#AWS WAF#Firewall#Intermediate
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