Catégorie : Azure

Restricting Pod Access to Azure IMDS (Preview)

In the world of Kubernetes on Azure, there’s been a longstanding default: any pod in your AKS cluster can query the Azure Instance Metadata Service (IMDS). That’s powerful — but also risky. Today, Microsoft introduces a preview feature that lets you block pod access to IMDS, tightening your cluster’s security boundaries.

Why Restrict IMDS?

IMDS is a REST API that provides VM metadata: VM specs, networking, upcoming maintenance events, and (critically) identity tokens. Because it’s accessible by default (via IP 169.254.169.254), a pod that’s compromised or misbehaving could exploit this to pull sensitive information or impersonate the node’s identity. That’s a serious threat.

By limiting which pods can reach IMDS, you reduce the “blast radius” of potential vulnerabilities.

How the Restriction Works (Preview)

  • Non host network pods (hostNetwork: false) lose access to IMDS entirely once restriction is enabled.
  • Host network pods (hostNetwork: true) retain access (they share the same network space as the node).
  • Azure implements this via iptables rules on the node to block traffic from non-host pods.
  • Tampering with iptables (e.g. via SSH or privileged containers) can break enforcement, so best practices like disabling SSH or avoiding privileged pods come into play.

Limitations & Considerations

Because this is still in preview, there are a number of tradeoffs:

  • Many AKS add-ons do not support IMDS restriction (e.g. Azure Monitor, Application Gateway Ingress, Flux/GitOps, Azure Policy, etc.).
  • Windows node pools aren’t supported yet.
  • Enabling restriction on a cluster that uses unsupported add-ons will fail.
  • After enabling or disabling, you must reimage the nodes (e.g. via az aks upgrade --node-image-only) to apply or remove the iptables rules.
  • The feature is opt-in and isn’t backed by an SLA or warranty.

Getting Started: Enabling IMDS Restriction

  1. Use Azure CLI 2.61.0+ and install or update aks-preview.
  2. Register the IMDSRestrictionPreview feature and refresh the ContainerService provider.
  3. Ensure OIDC issuer is enabled on your cluster (required).
  4. To create a new cluster with this feature:az aks create ... --enable-imds-restriction
  5. To enable it on an existing cluster:az aks update ... --enable-imds-restriction Then reimage nodes for enforcement.
  6. To verify, deploy test pods with and without hostNetwork: true and attempt to curl IMDS — the non-host pods should fail, the host pods should succeed.
  7. To disable, run az aks update --disable-imds-restriction and reimage.

Final Thoughts

This new capability gives AKS users an additional layer of defense: limiting which pods can access VM metadata and identities.

Reference: https://learn.microsoft.com/en-us/azure/aks/imds-restriction

Maxime.

Behind the Scenes of Global Azure Quebec 2025: Organizing, Speaking, and Securing the Future of AI

This year, I had the privilege of organizing Global Azure Quebec 2025 and it was without a doubt one of the most energizing, rewarding, and thought-provoking events I’ve ever been part of.

What started as a community gathering has grown into something truly special. We welcomed cloud engineers, architects, developers, students, and security professionals from all across Quebec (and beyond), all coming together to share knowledge, connect with peers, and dive deep into the future of Azure, AI, and cloud security.

A Community-Driven Event with Real Impact

Organizing this year’s event was no small feat—but every late-night planning call, every speaker coordination thread, every sponsorship pitch… it all paid off. Seeing a packed room full of curious minds, people asking the hard questions, and genuine hallway conversations made it worth every second.

Our sessions spanned everything from cloud-native app development to AI tooling, governance, platform engineering, and cybersecurity. The local talent we had on stage was simply incredible. I’m proud we could give them a platform—and equally proud of the strong turnout and engagement from the audience.

Alongside organizing, I also had the chance to present one of my current research interests: AI Red Teaming.

My session, titled « Security Risks for Generative AI », explored how we can build autonomous, LLM-powered agents to simulate adversarial behavior and proactively test the security of GenAI workloads.

In short, the AI Red Teaming Agent is designed to:

  • Simulate prompt injection and data leakage scenarios
  • Stress test model outputs for toxicity, hallucination, and jailbreaks
  • Integrate into security pipelines for continuous red teaming
  • Generate structured findings and map them to frameworks like MITRE ATLAS

The idea is simple but powerful: if AI is going to be used to build things, it should also be used to break them ethically, of course.

The feedback was amazing. Many attendees were intrigued (and maybe a little concerned) by the offensive potential of AI. But more importantly, there was a strong appetite for building defensible, auditable, and secure GenAI pipelines.

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Looking Ahead

Global Azure Quebec 2025 confirmed what I already knew: our community is ready for the next phase of cloud innovation—but it must be built with security in mind.

As we embrace AI, we also need to invest in the offensive side of security research to understand our weaknesses before attackers do. That’s where AI red teaming comes in. And that’s the conversation I’ll keep pushing forward.

To everyone who attended, supported, or helped behind the scenes—thank you. I can’t wait to see where we take this next.

Until then, stay curious, stay secure.

Maxime.

DevOpsCloudJunction Meetup | Kubernetes 1.31 Security Highlights: What You Need to Know!

Hi,

I had the pleasure of being a speaker at the inaugural DevOpsCloudJunction Meetup, and I wanted to take a moment to share my experience and insights from the event.

The DevOpsCloudJunction Meetup brought together passionate professionals from various sectors of the tech industry, all eager to share knowledge and discuss the latest trends in DevOps and cloud technology. It was an exciting opportunity to connect with fellow enthusiasts, exchange ideas, and learn from one another.

During my session, I explored a subset of security features released in Kubernetes 1.31. I believe that sharing our experiences and challenges is crucial in this ever-evolving field, and I’m grateful for the chance to contribute to that dialogue.

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Thank you, Sathish, for this wonderful speaking opportunity. I also want to extend my gratitude to everyone who participated and contributed to making this meetup a success. I look forward to seeing you all at future events!

Maxime.