In Amazon Web Services

Understanding Perimeter Security

Aaron C. Newman

Founder, CloudCheckr

Aaron.Newman@CloudCheckr.com

Changing Your Perspective

• How do I securing my business applications in AWS?

• Moving to the cloud =• Rethinking your perimeter security

• Rethinking how you perform most security tasks:

• Network-based IPS/IDS

• Network scanning

• Penetration tests

• Vulnerability assessments

In the Data Center

• Setting Up Perimeter Security:• Setting up your infrastructure

• Setting up access points to the internet

• Configuring firewall, IDS, IPS, etc.. at the access points

• Auditing Your Perimeter Security:• Gather set of IP Address blocks to poke at

• Do a port scan (using tools such as Nmap)

• Determine which ports are open on the target

• Try various exploits on the open ports.

• Sniff lots of packets

• Dig around to make sure no back doors into the network• Wireless access points, secondary T1 lines, DSL connections

• VPN access from some other network

AWS: What’s Different?

• Physical assets secured at the • AWS availability zone

• But we still need to guarding the AWS API• IAM Access is your new physical security

The idea of physical security morphs as

infrastructure becomes virtualized by AWS APIs.

In a new world of ephemeral, auto-scaling infrastructure,

you need to adapt your security architecture to meet

both compliance and security threats.

Minimizing Attack Vectors

• Principles don’t change• Reduce your surface area!

• Defense-in-depth

• Some attack vectors don’t change• Application level (user-privilege escalation, web app vulns, XSS)

• Operating system vulnerabilities

• Database vulnerabilities

• Some attack vectors change• Homogeneous environment

• Polymorphic targets/mapping

• Reduced network sniffing

Perimeter Assessments In the Cloud

• How do I assess the perimeter of my cloud?

• Old world – nmap, port scans, ping sweeps, etc…

• Give me your network block

• New world – let me see your configuration

• List of publicly-accessible resources

• Security groups (EC2-Classic, EC2-VPC, Redshift, RDS, etc…)

• Routing tables, Network ACL

• VPC, subnets

• S3 buckets and permissions

• IAM policies

Rules For Running Pen Tests on AWS

http://aws.amazon.com/security/penetration-testing/

• “complete and submit the AWS Vulnerability / Penetration Testing Request Form to request authorization for penetration testing or scanning of your resources”

• CaveatsAt this time, our policy does not permit testing m1.small or t1.micro instance types. This is to prevent potential adverse performance impacts on the resources you may be sharing with other customers in a multi-tenant environment.

• Demohttps://portal.aws.amazon.com/gp/aws/html-forms-controller/contactus/AWSSecurityPenTestRequest

• Need to know– IP Addresses to be scanned (Destination)

– Instances IDs

– Scanning IP addresses (Source)

What are we missing?

• This assumes our only threat is EC2

• AWS is a complex system w/ many, many moving parts

• Over 30 different AWS services • Many have unique access control systems

• Some companies have 100s of AWS accounts

• We need a complete inventory• all publicly-accessible endpoints and resources

Hackers find the single weak link

EC2-Classic

• EC2-Classic only available in old accounts

• Prevalent for early adopters

• Pre-VPC era

• Each EC2 instance has • A public IP address and a public DNS name

• A private IP address and a private DNS name

• Can have an Elastic IP Addresses

• Only security is EC2-Classic security groups

• Treat each as a target with its own security risk

EC2-VPC

• Default VPC is created in every region

• VPCs are wide open by default

• VPC is composed of:

• Internet and VPN gateways – connect to the rest of the world

• 1+ subnet(s)

• Routing table – how to move traffic around the VPC

• Network ACLs – a firewall but stateless

• Security groups – host-based firewall stateful

• Resources – EC2, RDS, Redshift, ElastiCache

S3 (Simple Storage Service)

• Up to 100 buckets in an account• Unlimited number of objects (billions is not uncommon)

• Location• Within a region, across multi-AZs, not housed in a VPC

• Can’t sit between client and storage

• Security• Access control thru IAM policies, bucket policies, ACLs, and query string authentication

• Server-side Encryption, HTTPS support

• Server-access logs (does not integrate with CloudTrail)

• Don’t grant FULL_CONTROL, WRITE_ACP, WRITE bucket permissions to Everyone EVER!!!

• Inventory your sensitive data

RDS (Relational Database Service)

• Location• Within a VPC or not, multi-AZ or not

• Security Options• DB Security Groups (if not in a VPC) or EC2-VPC Security Groups

• Select a non-default database port

• Publicly Accessible option • Not a good idea, but if you do this

• Make sure you use security groups to restrict source IP address

• Make sure you have latest patches applied

• Secure you database snapshots• Keys to the kingdom if someone can get a copy

• Brute-force passwords, restore to their own account

SQS (Simple Queuing Service)

• Where does SQS live?

• Within a region, not within a VPC

• Uses a URL such as

• https://sqs.us-east-1.amazonaws.com/123456789012/MySQS

• Security based on policy documents:

{

"Version": "2008-10-17",

"Id": "arn:aws:sqs:us-east-1:123456789012:MySQS/SQSDefaultPolicy",

"Statement": [

{

"Sid": "Sid1415217272568",

"Effect": "Allow", "Principal": { "AWS": "*" },

"Action": [

"SQS:ReceiveMessage", "SQS:SendMessage"

],

"Resource": "arn:aws:sqs:us-east-1:123456789012:MySQS"

},

SNS (Simple Notification Service)

• SNS does not live inside your VPC

• Permissions based on topic policies:

Using CloudTrail

• An AWS Service that records each time the AWS API is called• Currently supports 20+ AWS services • http://docs.aws.amazon.com/awscloudtrail/latest/userguide/dochistory.html

• Conveniently everything in AWS goes through the API• Even actions in the Management Console go through the API

• CloudTrail writes files into an S3 bucket• Near real-time (every five minutes)

• Files are in JSON format

Get started at http://aws.amazon.com/cloudtrail/

Internal vs. External threats

• Understanding who the threat is

• Internal threats

• Disgruntled or malicious DevOps

• E.g. Edward Snowden

• External threats

• Hacker groups, script kiddies

• E.g. Anonymous

Each requires different controls and monitoring

Tools For Securing AWS

• Generic tools fall short

• Purpose-built, not cloud-washed• Make sure tools don’t fall over in the cloud

• Tools have to understand dynamic, ephemeral IPs

• Need a deep understanding of AWS• What does this means

• Context is important

• Actionable intelligence

Questions?

Questions on:

• AWS Security

• CloudCheckr

Thank You for Attending

Sign up today for free evaluationat http://cloudcheckr.com

Aaron Newman is the Founder of CloudCheckr (www.cloudcheckr.com)

Please contact me with additional questions at:aaron.newman@cloudcheckr.com