Connect with us

Hi, what are you looking for?


Cloud Security

Vulnerabilities in Google Kubernetes Engine Could Allow Cluster Takeover

Two flaws in Google Kubernetes Engine could be exploited to escalate privileges and take over the Kubernetes cluster.

An attacker with access to a Kubernetes cluster could chain two vulnerabilities in Google Kubernetes Engine (GKE) to escalate privileges and take over the cluster, cybersecurity firm Palo Alto Networks reports.

The issues, which may not pose a significant risk on their own, were identified in FluentBit, the default logging agent in GKE, and in Anthos Service Mesh (ASM), an optional add-on for controlling service-to-service communication within the environment.

A lightweight log processor and forwarder, FluentBit has been the default logging agent in GKE since March 2023, being deployed as a DaemonSet (controller) from the get-go. ASM is Google’s implementation of the Istio Service Mesh open source project, used for the management and visualization of services.

The recently identified vulnerabilities in FluentBit and ASM, Palo Alto Networks says, can be exploited as part of the second-stage of an attack, provided that the attacker has achieved remote code execution in the FluentBit container or that they can break out of another container.

“If an attacker has the ability to execute in the FluentBit container and the cluster has ASM installed, they can create a single powerful chain to gain complete control of a Kubernetes cluster. Attackers can use this access to conduct data theft, deploy malicious pods and disrupt the cluster’s operations,” Palo Alto Networks explains.

A misconfiguration in FluentBit could allow an attacker to use the token of any pod in the node to impersonate the pod, gain unauthorized access to the cluster, and list all running pods.

“Besides gaining unauthorized access to the cluster, an attacker can escalate their privilege or perform harmful actions. In fact, this gives the attacker a huge attack surface, depending on the permissions of the neighboring pods in the node,” Palo Alto Networks says.

Furthermore, the cybersecurity firm discovered that, post installation, the ASM’s Container Network Interface (CNI) DaemonSet retains excessive permissions, allowing an attacker to create a new pod with these permissions and gain privileged access to the cluster.

Advertisement. Scroll to continue reading.

By exploiting the FluentBit issue, an attacker can map the cluster to find the Istio container, and abuse ASM CNI DaemonSet’s excessive permissions to create a ‘powerful’ pod, target a service account with high privileges, and obtain permissions to act as a cluster administrator.

On December 14, Google announced patches for both issues, urging users to manually update their clusters and node pools. GKE versions 1.25.16-gke.1020000, 1.26.10-gke.1235000, 1.27.7-gke.1293000, and 1.28.4-gke.1083000, and ASM versions 1.17.8-asm.8, 1.18.6-asm.2, and 1.19.5-asm.4 resolve the bugs.

“These vulnerabilities are not exploitable on their own in GKE and require an initial compromise. We are not aware of any instances of exploitation of these vulnerabilities,” Google notes in its advisory.

Related: Researchers Discover Dangerous Exposure of Sensitive Kubernetes Secrets

Related: Kubernetes Vulnerability Leads to Remote Code Execution

Related: Attackers Abuse Kubernetes RBAC to Deploy Persistent Backdoor

Written By

Ionut Arghire is an international correspondent for SecurityWeek.


Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Gain valuable insights from industry professionals who will help guide you through the intricacies of industrial cybersecurity.


Join us for an in depth exploration of the critical nature of software and vendor supply chain security issues with a focus on understanding how attacks against identity infrastructure come with major cascading effects.


Expert Insights

Related Content

Application Security

Cycode, a startup that provides solutions for protecting software source code, emerged from stealth mode on Tuesday with $4.6 million in seed funding.


Less than a week after announcing that it would suspended service indefinitely due to a conflict with an (at the time) unnamed security researcher...

Data Breaches

OpenAI has confirmed a ChatGPT data breach on the same day a security firm reported seeing the use of a component affected by an...

IoT Security

A group of seven security researchers have discovered numerous vulnerabilities in vehicles from 16 car makers, including bugs that allowed them to control car...


A researcher at IOActive discovered that home security systems from SimpliSafe are plagued by a vulnerability that allows tech savvy burglars to remotely disable...

Risk Management

The supply chain threat is directly linked to attack surface management, but the supply chain must be known and understood before it can be...

CISO Conversations

SecurityWeek talks to Billy Spears, CISO at Teradata (a multi-cloud analytics provider), and Lea Kissner, CISO at cloud security firm Lacework.


Patch Tuesday: Microsoft calls attention to a series of zero-day remote code execution attacks hitting its Office productivity suite.