Securing Network Traffic & AWS Service Endpoints

Securing network traffic in AWS ensures data integrity, confidentiality, and availability by controlling how traffic flows between resources and external connections. SecureCart follows AWS best practices to:

✔ Prevent unauthorized access by securing traffic within its VPC. ✔ Encrypt data in transit using TLS and VPN tunnels. ✔ Use private connectivity options (VPC Endpoints, PrivateLink) to reduce reliance on the public internet. ✔ Restrict external access to critical AWS services and applications.

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🔹 Step 1: Securing Network Traffic in AWS

AWS provides multiple network security controls to manage inbound and outbound traffic, prevent unauthorized access, and protect sensitive data.

Security Mechanism	Purpose	SecureCart Implementation
Security Groups	Control instance-level traffic	ALB allows only HTTP/HTTPS; RDS allows only backend access.
Network ACLs (NACLs)	Enforce subnet-level traffic control	Blocks SSH from unknown IPs, restricts outbound traffic.
AWS WAF	Protects ALB & API Gateway from SQL Injection, XSS attacks	SecureCart API Gateway blocks malicious requests.
AWS Shield	DDoS protection	ALB & CloudFront are protected against volumetric attacks.
VPC Peering	Secure, direct connectivity between VPCs	SecureCart connects its main application VPC to the payment processing VPC.
AWS Transit Gateway	Centralized routing for multi-VPC environments	SecureCart enables secure communication between different workload accounts.

✅ Best Practices: ✔ Use Security Groups to allow only required traffic. ✔ Implement AWS WAF to block web-based threats. ✔ Use AWS Shield for automatic DDoS protection.

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🔹 Step 2: Encrypting Network Traffic (Data in Transit Security)

✔ Why encrypt network traffic? – Protects sensitive data from interception during transmission. ✔ How SecureCart secures data in transit:

Encryption Method	Description	Use Case in SecureCart
TLS (HTTPS)	Encrypts web traffic between clients & ALB/API Gateway.	SecureCart’s frontend enforces HTTPS for all user traffic.
AWS Certificate Manager (ACM)	Manages TLS certificates automatically.	ALB & API Gateway use ACM for SSL termination.
IPsec VPN	Encrypts traffic between AWS & on-premises data centers.	SecureCart uses VPN to securely connect its office network.
AWS Direct Connect	Provides a dedicated private connection.	SecureCart uses Direct Connect for faster and more secure data transfer with third-party logistics providers.

✅ Best Practices: ✔ Use TLS (HTTPS) for all public endpoints. ✔ Rotate SSL certificates automatically using AWS Certificate Manager. ✔ Use VPN/Direct Connect for secure private network connections.

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🔹 Step 3: Using AWS Service Endpoints Securely

AWS services such as S3, DynamoDB, and Secrets Manager can be accessed privately using VPC Endpoints to eliminate public exposure.

A. Why Use VPC Endpoints?

✔ Avoids internet exposure – Service traffic stays within AWS. ✔ Reduces latency & cost – No need for a NAT Gateway or public internet bandwidth. ✔ Improves security – Traffic cannot be intercepted via the internet.

AWS Service	Endpoint Type	Use Case in SecureCart
Amazon S3	VPC Gateway Endpoint	SecureCart backend services fetch images from S3 privately.
DynamoDB	VPC Gateway Endpoint	SecureCart logs orders to DynamoDB without public internet access.
Secrets Manager	VPC Interface Endpoint	SecureCart retrieves database credentials privately via Secrets Manager.

✅ Best Practices: ✔ Use VPC Endpoints to keep AWS service traffic private. ✔ Apply IAM policies to restrict access to VPC Endpoints.

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🔹 Step 4: Restricting Outbound Internet Access from AWS Resources

Many workloads do not need internet access, but they might require updates or communicate with third-party APIs. SecureCart controls outbound internet access by:

✔ Blocking unnecessary outbound traffic using Security Groups & NACLs. ✔ Using NAT Gateway for outbound traffic when internet access is required. ✔ Restricting direct internet access from private subnets.

A. SecureCart NAT Gateway Setup

Subnet	Internet Access?	Traffic Flow
Public Subnet (ALB)	✅ Allowed	ALB can accept internet traffic
Private Subnet (ECS, RDS)	❌ Denied	No direct internet access; outbound traffic goes through NAT Gateway

✅ Best Practices: ✔ Place NAT Gateway in a public subnet and route outbound traffic through it. ✔ Restrict outbound internet access using Security Groups and NACLs.

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🔹 Step 5: Securing API & Application Traffic

API traffic is a common attack vector. SecureCart protects API communications using:

A. AWS WAF (Web Application Firewall)

✔ Blocks SQL Injection, Cross-Site Scripting (XSS), and bot attacks. ✔ SecureCart protects API Gateway & ALB using AWS WAF rules.

AWS WAF Rule	Threat Protection
SQL Injection Protection	Blocks malicious SQL payloads.
XSS Protection	Blocks Cross-Site Scripting (XSS) attacks.
Rate Limiting	Prevents brute force & bot attacks.

B. AWS Shield

✔ Defends against DDoS attacks. ✔ SecureCart’s ALB and API Gateway are automatically protected by AWS Shield Standard.

✅ Best Practices: ✔ Use AWS WAF managed rules for common security threats. ✔ Enable AWS Shield Advanced for critical applications that require enhanced DDoS protection.

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🔹 Step 6: Secure External Network Connectivity

SecureCart ensures private, secure access to AWS services and third-party providers.

A. AWS PrivateLink (Private API Communication)

✔ SecureCart connects third-party payment providers via PrivateLink to ensure API calls do not go over the internet.

B. AWS Direct Connect (On-Premises Connectivity)

✔ SecureCart uses Direct Connect to securely integrate with a third-party logistics system.

Scenario:

SecureCart must ensure secure communication between AWS services while minimizing exposure to the public internet.

Key Learning Objectives:

✅ Secure API calls using AWS VPC Endpoints ✅ Implement Security Groups and Network ACLs for controlled access ✅ Configure Route Tables for efficient network traffic flow ✅ Protect AWS applications using firewall rules and encryption

Hands-on Labs:

1️⃣ Create VPC Endpoints for S3 & DynamoDB to Prevent Internet Traffic 2️⃣ Configure Security Groups & Network ACLs for EC2 & RDS 3️⃣ Implement Route Tables for Isolated Application Traffic

🔹 Outcome: SecureCart ensures that AWS service communications stay private while securing network access.