Arp Spoofing on Aws

Remediating ARP spoofing in Aws environments requires a multi-layered approach using Aws-native security features. The primary defense is architectural isolation combined with strict network controls.

Effective remediation includes:

• Enable VPC flow logs to monitor all network traffic
• Restrict instance metadata service access using IMDSv2 with hop limits
• Implement security groups that explicitly deny ARP traffic between instances
• Use AWS Network Firewall to block suspicious network patterns
• Deploy AWS GuardDuty for continuous threat detection

Code-level fixes using Aws SDKs:

import boto3
from botocore.exceptions import ClientError

def secure_vpc_configuration(vpc_id):
    ec2 = boto3.client('ec2')
    
    # Restrict metadata service access
    try:
        ec2.modify_instance_metadata_options(
            InstanceIds=[instance_id],
            HttpTokens='required',
            HttpPutResponseHopLimit=2
        )
    except ClientError as e:
        print(f"Metadata modification failed: {e}")
    
    # Create security group with ARP restrictions
    response = ec2.create_security_group(
        GroupName='arp-restriction-sg',
        Description='Restricts ARP spoofing',
        VpcId=vpc_id
    )
    group_id = response['GroupId']
    
    # Revoke ARP traffic between instances
    ec2.authorize_security_group_ingress(
        GroupId=group_id,
        IpPermissions=[{
            'IpProtocol': 'arp',
            'FromPort': -1,
            'ToPort': -1,
            'UserIdGroupPairs': [{
                'GroupId': group_id,
                'VpcId': vpc_id
            }]
        }]
    )
    return group_id

This code demonstrates how to programmatically secure your Aws environment against ARP spoofing by restricting metadata access and creating security groups that prevent ARP traffic between instances in the same VPC.