10 Tips for Cloud Native Security

1
10 Tips for
Cloud Native Security
Karthik Gaekwad
Austin Developer Week 2018
DevSecOps in a
Cloud Native World
Karthik Gaekwad
@iteration1
Devnet Create 2019

•I’m Karthik Gaekwad
•NOT a DBA
•Cloud Native Evangelist at Oracle Cloud
•https://cloudnative.oracle.com/
•Past: Developer on the Oracle Managed
Kubernetes Team
Hello
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Hello
• Been in Industry 15 years.
• In general, I like building stuff with friends.
• Maintainer for Gauntlt- Open source security scanner.
• Love Teaching and building community.
• Run Devopsdays Austin, Container Days, Cloud Austin.
• Chair All Day Devops Cloud Native track.
• LinkedIn Learning Author for Learning Kubernetes (and more).
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The Cloud Native Journey
4
Phase I
Developer Focus
Phase II
DevOps Focus
Phase III
Business Focus
(end-to-end)
Container Adoption Application Deployment Intelligent Operations
SpeedEfficiencyAgility
Docker
Kubernetes
Core to Edge
Developer adoption
Dev/Test apps
Simple orchestration
Individual developers
DevOps deployment
Production apps
Advanced orchestration
Teams & lines of business
End-to-end integration
Digital business apps
Serverless, DevSecOps, & ML
Cloud native enterprises
Focus
Applications
Automation
Community
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CNCF Survey: August 2018
How Does Your Company Use Containers and Where?
Lots of adoption on
dev/staging
Continued production
increase
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CNCF Survey: August 2018
How Does Your Company Use Containers and Where?
Adoption over public and on-prem
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Kubernetes Dominates Container
Management
Your company/organization manages
containers with:
Winner!
Kubernetes
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Top 5 challenges to cloud native adoption…
0 5 10 15 20 25 30 35 40 45
Complexity
Cultural Challenges
Lack of Training
Security
Monitoring
Percentages
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• Managing, maintaining, upgrading Kubernetes Control
Plane
• API Server, etcd, scheduler etc….
• Managing, maintaining, upgrading Kubernetes Data
Plane
• In place upgrades, deploy parallel cluster etc….
• Figuring out container networking & storage
• Overlays, persistent storage etc… - it should just work
• Managing Teams
• How do I manage & control team access to my clusters?
• Security, security, security
9
Kubernetes & Cloud Native Challenges
Source: Oracle Customer Survey 2018
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How Are Teams Addressing Complexity, Training Issues?
App Management
Upgrades & Patching
Platform Backup &
Recovery
High Availability
Scaling
App Deployment
Power, HVAC
Rack and Stack
Server Provisioning
Software Installation
Customer Managed Fully-Managed
App Management
Upgrades & Patching
Platform Backup &
Recovery
High Availability
Scaling
App Deployment
Power, HVAC
Rack and Stack
Server Provisioning
Software Installation
 Faster Time to Deploy
 Lower Risk
 Accelerate Innovation
Fully managed
Benefits
YOU
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Which brings us to security…

Unsecured K8s dashboards
• Unsecured Kubernetes
Dashboard with account creds.
• Used this to mine
cryptocurrency.
• 2017: Aviva
• 2018: Tesla, Weight Watchers
• https://redlock.io/blog/cryptojacking-
tesla
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Kubelet credentials hack
• Shopify: Server Side request
Forgery
• Get kubelet certs/private key
• Root access to any container in
part of infrastructure.
• https://hackerone.com/reports/341876
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CVE’s Happen…
Even more relevant with increased
production usage of containers…
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CVE’s Happen…
Container
Escaping
Privilege
Escalation
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“Kubernetes is too complicated”

“Kubernetes is too complicated”
“We hope it’ll get easier”

Let’s look at:
•Attack Surface
• More importantly, how to limit damage
•Security related features in K8s
• The more you know, the better you build
•Opensource Tooling to help
• Because we all need help

Attack Surface
Goal: Reduce the attack surface
•Analysis for:
•Host(s)
•Container (Images and running)
•Kubernetes Cluster
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Attack Surface: Host
• These are the machines you’re running Kubernetes on.
• Age old principles of Linux still apply:
• Enable SELinux
• AppArmor
• Seccomp
• Hardened Images
• Goal: Minimize privilege to applications running on the host
• Good news: Already a wealth of information on this subject!
• http://lmgtfy.com/?q=how+to+reduce+attack+surface+linux
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Attack Surface: Container Images
GOAL: Know your base image when
building containers
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GOAL: Know your base image when building containers
**BTW, this is just a ruby helloworld app @iteration1

Full disclosure: I’m karthequian; I created this as a ruby 101 container for learning purposes only
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• When in doubt, stick to an official images!
• Or start from a sane base image (example: alpine linux)
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GOAL: Smaller the image, the better
• Less things for an attacker to exploit.
• Quicker to push, quicker to pull.
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GOAL: Don’t rely on :latest tag
• :latest image yesterday might not be :latest image tomorrow
• Instead, you’d want to know what specific version you’re operating
with.
• Side benefit: If there is a new vulnerability announced for OS version
x.y.z, you know immediately whether you’re running that version!
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GOAL: Check for vulnerabilities
periodically
• Plenty of ways to do this in registries. We’ll cover more in the tooling
section
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Attack Surface: Running Containers
GOAL: Don’t run as root
• Containers running as root might be completely unnecessary for the
actual application.
• If compromised, attacker can do a lot more things..
• Pod security policies can help (we’ll see how later).
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Attack Surface: Running Containers
GOAL: Limit host mounts
• Be wary of images that require broad access to paths on the host.
• Limit your host mount to a smaller subset of directories.
• Reduces blast radius on compromise.
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Attack Surface:
Kubernetes Cluster

Kubernetes Cluster- TLS
TLS ALL THE THINGS
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• TLS Checklist:
1. User and Master
2. Nodes and Master
3. Everything etcd
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CVE’s
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GOAL: Have an upgrade strategy
• Because…CVE’s are fixed in new minor versions.
• Don’t treat K8s as “install once, run all the time”.
• Make your K8s install repeatable for different versions.
• ..Or use a Managed Provider.
• Either automatically patch for you, or tell you what to do.
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We’re a little
better off now.
But what else to do?

K8s Features
How can the platform help
me make secure choices?
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K8s Features
• Kubernetes Secrets
• Authentication
• Authorization
• Audit Logging
• Network Policies
• Pod security policies
• Open Policy Agent
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Kubernetes Secrets
• GOAL: Use Kubernetes secrets to store sensitive data instead of
config maps.
• Also look at: secrets encryption provider.
• Controls how etcd encrypts API data
• --experimental-encryption-provider-config
• https://kubernetes.io/docs/tasks/administer-cluster/encrypt-data/
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Authentication and Authorization
• Do you know how you are authenticating with Kubernetes?
• Many ways to Authenticate
• Client Certs
• Static token file
• Service Account tokens
• OpenID
• Webhook Mode
• And more (https://kubernetes.io/docs/reference/access-authn-authz/authentication/)
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Whatever you do,
DO NOT YOLO!
Goal: Pick a strategy that fits
your use case

You can pick an authz strategy..
If you DO NOT YOLO…

https://kubernetes.io/docs/reference/acc
ess-authn-authz/authorization/
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• Pro tip: Nobody uses ABAC anymore. Don’t be that guy….
• RBAC is the defacto standard
• Based on roles and role bindings
• Good set of defaults: https://github.com/uruddarraju/kubernetes-rbac-policies
• Can use multiple authorizers together, but can get confusing.
• 1st authorizer to authorize passes authz
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Kubernetes Cluster- Audit Logs
• Wat?
• “Kubernetes auditing provides a security-relevant chronological set of
records documenting the sequence of activities that have affected
system by individual users, administrators or other components of the
system.”
• Answers: What/when/who/where information on security events.
• Your job: Periodically watch Kubernetes Audit logs
• https://kubernetes.io/docs/tasks/debug-application-cluster/audit/
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Kubernetes Cluster- Network Policies
• Consider adding a network policy to the cluster…
• Default Policy: All pods can talk to all other pods.
• Consider limiting this with a Network Policy
• https://kubernetes.io/docs/concepts/services-networking/network-policies/
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Kubernetes Cluster- Pod Security Policies
• Consider adding Pod Security policies
• PodSecurityPolicy: A Defined set of conditions a pod must run with.
• Think of this as authorization for pods.
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Kubernetes Cluster: Pod Security Policies
https://kubernetes.io/docs/concepts/policy/pod-security-policy/#what-is-a-pod-security-policy
Capability for an
admin to
control specific
actions
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Open Policy Agent
• Policy based control for your whole environment.
• Full featured Policy Engine to offload policy decisions from each
application/service.
• Deploy OPA alongside your service
• Add policy data to OPA’s store
• Query OPA on decisions.
• Great idea, still early, watch this space…
• Standardize policies for all clusters
• https://www.openpolicyagent.org/
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Keep tabs on the CNCF Security landscape
https://landscape.cncf.io/landscape=security-complia

CNCF Projects
• “The Update Framework”
• Is a framework or a
methodology.
• Used for secure software
updates.
• Based on ideas surrounding trust
and integrity.
• Is a project.
• Based on TUF.
• A solution to secure software
updates and distribution.
• Used in Docker Trusted Registry.
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Clair
• Open source project for the static analysis of vulnerabilities in
containers.
• Find vulnerable images in your repo.
• Built into quay.io, but you can add to your own repo.
• https://github.com/coreos/clair
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Harbor
• Newer! CNCF Project
• Registry product
• Supports vulnerability scanning,
image signing and identity
control
• Scope is larger than clair
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Kube-bench
• Checks whether a Kubernetes cluster is deployed according to
security best practices.
• Run this after creating your K8s cluster.
• https://github.com/aquasecurity/kube-bench
• Defined by the CIS Benchmarks Docs: https://www.cisecurity.org/cis-
benchmarks/
• Run it against your Kubernetes Master, or Kubernetes node.
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Kube-bench example
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Kubesec
• Helps you quantify risk for Kubernetes resources.
• Run against your K8s applications (deployments/pods/daemonsets
etc)
• https://kubesec.io/ from controlplane
• Can be used standalone, or as a kubectl plugin
(https://github.com/stefanprodan/kubectl-kubesec)
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Kubeaudit
• Opensourced from Shopify.
• Auditing your applications in your K8s cluster.
• https://github.com/Shopify/kubeaudit
• Little more targeted than Kubesec.
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Put it all together…
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Apply It!
72
• Day 1:
• Know what version of Docker and Kubernetes you use.
• Understand if your control and data plane nodes are
hardened.
• Understand how your Docker containers are built.
• Find out how you authenticate and authorize for your
clusters.
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Apply It!
73
•Week 1:
•Build an Automation Pipeline:
• To build Docker images on code pushes
• Versioning strategy for code
• To build your Kubernetes clusters
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Apply It!
74
•1st Month
•Sanitize your code:
• Know your base images
• Implement versioning for your containers
• Invest in a registry (or tooling) that does vulnerability
scanning
•Kubernetes:
• Have an upgrade strategy in place
• Analyze secrets/sensitive cluster data
• Turn on audit logging
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Apply It!
75
• 3 Months:
• Continuously Monitor
• Tooling like Kubesec/Kube-audit
• Plan how to address vulnerabilities/CVE’s
• K8s:
• Strategy for Pod Security Policies
• Strategy for Network Policies
• Run scans (like kube-bench) on cluster creation
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Apply It!
76
•6 Months:
•Re-ask day 1 questions.
•Review strategies- is it working? What needs
tweaking?
•Review tooling- are there new tools that help? Are
existing tools working?
•Review CVE’s
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Couple more resources to look at:
• 11 ways not to get hacked:
https://kubernetes.io/blog/2018/07/18/11-ways-not-to-get-hacked
• K8s security (from Image Hygiene to Network Policy):
https://speakerdeck.com/mhausenblas/kubernetes-security-from-
image-hygiene-to-network-policies
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KEEP CALM
AND
KUBE ON
@iteration1

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