CVE-2022-24878 in Flux
Summary
by MITRE • 05/06/2022
Flux is an open and extensible continuous delivery solution for Kubernetes. Path Traversal in the kustomize-controller via a malicious `kustomization.yaml` allows an attacker to cause a Denial of Service at the controller level. Workarounds include automated tooling in the user's CI/CD pipeline to validate `kustomization.yaml` files conform with specific policies. This vulnerability is fixed in kustomize-controller v0.24.0 and included in flux2 v0.29.0. Users are recommended to upgrade.
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Analysis
by VulDB Data Team • 05/08/2022
The vulnerability identified as CVE-2022-24878 affects Flux, an open and extensible continuous delivery solution for Kubernetes environments. This issue specifically targets the kustomize-controller component within the Flux ecosystem, which is responsible for managing and applying Kubernetes configurations through kustomization files. The flaw manifests as a path traversal vulnerability that can be exploited through maliciously crafted kustomization.yaml files, potentially compromising the stability and availability of the entire delivery pipeline.
This vulnerability represents a critical security flaw that enables attackers to manipulate the kustomize-controller's file system operations through carefully constructed path references in kustomization.yaml configuration files. The technical implementation of this vulnerability stems from insufficient input validation and sanitization within the controller's processing logic, allowing malicious path traversal sequences to bypass normal access controls. The flaw operates at the controller level, meaning that successful exploitation can lead to complete system compromise rather than just individual resource manipulation. The path traversal mechanism allows attackers to navigate beyond intended directories and potentially access or manipulate files that should remain restricted, creating a significant risk for continuous delivery systems that rely on automated configuration management.
The operational impact of this vulnerability extends beyond simple denial of service, as it can potentially allow attackers to disrupt the entire Kubernetes delivery pipeline. When exploited, the vulnerability can cause the kustomize-controller to process malicious file paths that result in resource exhaustion, system instability, or unauthorized access to sensitive configuration data. The controller's role in continuous delivery makes this particularly dangerous as it can affect the integrity of deployment processes and potentially provide attackers with persistent access to the target environment. Organizations relying on Flux for automated deployments face significant risk of service disruption and potential data exposure when this vulnerability is present in their systems.
The remediation for CVE-2022-24878 involves upgrading to kustomize-controller version 0.24.0 or later, which includes the necessary patches to address the path traversal vulnerability. This fix is also incorporated in flux2 version 0.29.0, making it essential for users to perform the upgrade to protect their systems. The vulnerability is classified under CWE-22, which specifically addresses path traversal flaws in software systems, and aligns with ATT&CK technique T1059.001 for executing malicious code through command injection. Organizations should implement additional security controls including automated validation of kustomization.yaml files within their CI/CD pipelines as a defensive measure, though this represents a workaround rather than a complete solution. The vulnerability highlights the importance of validating configuration files in automated deployment systems and demonstrates how seemingly benign configuration management tools can become attack vectors when proper input sanitization is lacking.