Sven Nobis on Insinuator.net - Bold Statements

CVE-2026-47237 – Overly Permissive Istio Permissions Allow Kubeflow Authorization Token Stealing

Wed, 20 May 2026 00:00:00 +0000

Kubeflow is vulnerable to the theft of authorization tokens by any user of the Kubeflow UI or APIs, such as the Dashboard, Pipelines API, or Notebooks. With this token, the attacker can take over the user’s account and the data that is processed by that user. The attacker needs a valid user with the kubeflow-edit or Contributor role in a random Kubeflow namespace to perform this attack. This is given if Automatic Profile Creation is enabled. A setup based on the official manifests prior to version 1.10, and on most other packaged Kubeflow distributions, is vulnerable.

The Istio edit permissions were removed by Kubeflow in a timely manner. Affected users should update to the latest version to mitigate this issue.

KubeCon + CloudNativeCon Europe 2026

Wed, 01 Apr 2026 00:00:00 +0000

Exactly one week ago, Sven and I had the incredible opportunity to give our very first talk at KubeCon + CloudNativeCon 2026: How To Break Multi-Tenancy Again and Again …and What We Can Learn From It. We discussed the challenges of namespace-based multi-tenancy and presented real-world exploits in Kubeflow, Istio, and Traefik that bypass threat boundaries between namespaces and workloads. Based on these problems, we developed a methodology to assess and address them. You can find the methodology discussed in the talk in detail in another blog post or on GitHub. You can also find the slides here.

Methodology for Assessing Kubernetes Namespace-Based Multi-Tenancy Setups

Thu, 26 Mar 2026 00:00:00 +0000

This page introduces our structured methodology for assessing security risks in Kubernetes environments that use Namespace-based Multi-Tenancy. It addresses weaknesses that break Namespace-based isolation that not well studied, yet. We found this issues during our research and presented them together with this methodology in our Talk at KubeCon + CloudNativeCon Europe 2026.

The methodology assumes that industry best practices, such as NetworkPolicies, Role-Based Access Control (RBAC), and Pod Security Standards, are already in place. These measures provide a necessary baseline level of protection against well-known isolation threats. However, they are insufficient to address a class of more subtle attack vectors arising from interactions between tenants and shared components. Such attack vectors may still compromise the confidentiality, integrity, and availability (CIA) of the cluster and its workloads, even in well-hardened environments.

Security Considerations on Istio’s CRDs with Namespace-based Multi-Tenancy

Wed, 25 Mar 2026 00:00:00 +0000

We reported a possible Man-in-the-Middle (MitM) attack scenario in which a VirtualService can redirect or intercept traffic within the service mesh. This affects Namespace-based Multi-Tenancy clusters where tenants have the permissions to deploy Istio resources (networking.istio.io/v1).

In collaboration with Istio, we published a guest submission in Istio’s blog (as well as below), a Security Bulletin, and an update to their Security Model to address this issue.

This blog post highlights the risks of using Istio in multi-tenant clusters and explains how users can mitigate these risks and safely operate Istio in their deployments.

Vulnerabilities in Broadcom VMware Aria Operations: Privilege Escalation (CVE-2025-41245 / CVE-2026-22721)

Wed, 18 Mar 2026 00:00:00 +0000

During a customer project, we identified privilege escalation vulnerabilities in Broadcom VMware Aria Operations. It is possible to escalate the privileges of an administrative vCenter user to an Aria administrator and take over systems integrated in Aria. Meaning, the vCenter user can gain privileged access to systems they have no access to. While both users might sound similarly privileged, this is not true in most environments – especially not in complex corporate environments: An insignificant vCenter user in a development environment can take over all other vCenters in a complex corporate environment.

TROOPERS20 Training Teaser: Hacking 101

Thu, 07 Nov 2019 00:00:00 +0000

Hi there,
like in recent years the popular Hacking 101 workshop will take place on TROOPERS20, too! The workshop will give you an insight into the hacking techniques required for penetration testing. These techniques will cover various topics:

Information gathering
Network scanning
Web application hacking
Low-level exploitation

…and more!

During this workshop you will learn, step by step, a testing methodology that applies to the majority of scenarios. So imagine you have to assess the security of a system running on the Internet. How would you start? First, you need a good understanding of the target, including running services or related systems. Just scanning the target’s IP address will most likely not reveal all relevant information you can get. In the information gathering step, you will learn where you could find more relevant information than just a list of open ports. A brief understanding of the target and it’s related systems/services/applications will make scanning and identifying vulnerabilities a lot easier and more effective. Then, the last step will be the exploitation of the identified vulnerabilities, with the ultimate aim to get access to the target system and pivot to other, probably internal, systems and resources.

TROOPERS19 Training Teaser: Hacking 101

Mon, 14 Jan 2019 00:00:00 +0000

Hi there,
like in recent years the popular Hacking 101 workshop will take place on TROOPERS19, too! The workshop will give you an insight into the hacking techniques required for penetration testing. These techniques will cover various topics:

Information gathering
Network scanning
Web application hacking
Low-level exploitation

…and more!

nmap-parse-output: A tool for analyzing Nmap scans

Fri, 24 Aug 2018 00:00:00 +0000

tl;dr: With the tool nmap-parse-output you can convert, manipulate or extract data from a Nmap/masscan scan output. This allows you to get the information you’re looking for by just entering a straightforward command.

Preamble

A while ago, we had to scan a mass amount of IPs within a project for a customer. While it’s feasible to read the whole output of a Nmap scan if you have just a few alive hosts, this was not possible anymore for this mass amount of systems. We’ve started with a masscan to scan all 2^16 ports of the IP ranges and wanted to perform a more precise analysis of the alive hosts (which had responded to at least one SYN packet) with Nmap. The result of this scan grew to nearly a hundred megabyte and we now had to do an analysis of which ports we had to look deeper into and which are intended to be open.

TR17 Training: Hacking 101

Thu, 26 Jan 2017 00:00:00 +0000

Hi there,
Like in recent years the popular Hacking 101 workshop will take place on TROOPERS17, too! The workshop will give attendees an insight into the hacking techniques required for penetration testing. These techniques will cover various topics:

information gathering
network scanning
web application hacking
low-level exploitation

…and more!

During this workshop you will learn, step by step, a testing methodology that is applicable to the majority of scenarios. So imagine you have to assess the security of a system running on the Internet. How would you start? First, you need a good understanding about the target, including running services or related systems. Just scanning an IP will most likely not reveal a lot of information about the system. The gathered information may help you to identify communication relations of services that could include vulnerabilities. A brief understanding of the target and it’s related systems/services/applications will make scanning and identifying vulnerabilities a lot easier and more effective. Then, the last step will be the exploitation of the identified vulnerabilities, with the ultimate aim to get access to the target system and pivot to other, probably internal, systems and resources.

Jenkins Remoting RCE II – The return of the ysoserial

Fri, 01 Jul 2016 00:00:00 +0000

Jenkins is a continuous integration server, widely used in Java environments for building automation and deployment. The project recently disclosed an unauthenticated remote code execution vulnerability discovered by Moritz Bechler. Depending on the development environment, a Jenkins server can be a critical part of the infrastructure: It often creates the application packages that later will be deployed on production application servers. If an attacker can execute arbitrary code, s/he can easily manipulate those packages and inject additional code. Another scenario would be that the attacker stealing credentials, like passwords, private keys that are used for authentication in the deployment process or similar.

New Methods for Exploiting ORM Injections in Java Applications (HITB16)

Thu, 02 Jun 2016 00:00:00 +0000

The HITBSecConf or “Hack In The Box” in Amsterdam is a well known security conference in Europe. We also attended this year too, and there were quite some interesting talks at the HITBSecConf16 conference. One of the talks was about “New Methods for Exploiting ORM Injections in Java Applications” by the security researchers Mikhail Egorov and Sergey Soldatov.

I. What is Object-Relational Mapping (ORM)?

ORM stands for Object-Relational Mapping, which is a technique that automatically converts data from a relational database management system (RDBMS) into objects. This is often used in business applications of today.

Mind The Gap – Exploit Free Whitelisting Evasion Tactics

Thu, 31 Mar 2016 00:00:00 +0000

At the Troopers 16 Casey Smith has given a talk about the gap in Application Whitelisting.

Application Whitelisting is a technique that should prevent malware and unauthorized applications from running. Broadly speaking this is implemented by deciding if an application is trusted or not before executing it. Casey’s talk gave an understanding where this whitelisiting fails down.

In his introduction about the architecture he reminded us: There is no perfect defense. It is important to understand how the defenses work and where they fail. In the difference to exploits, which can be patched, there is no possibility to patch architecture flaws.

Towards a LangSec-aware SDLC

Thu, 31 Mar 2016 00:00:00 +0000

At the TROOPERS’15 Jacob l. Torrey held a track about LangSec-Aware Software Development Lifecycle. He talked about programming conventions and what tools can be used for enforcing the compliance. There is a lack of metrics to understand what make software more secure or less secure. His main goals was to show that LangSec has far-reaching impacts into software security and to give the audience a framework to transform the theory into practice. A SLDC should help to find bugs sooner in the development process and reduce defect rate in production thereby. A lower defect rate in production does not only improve security it also reduces costs.