CVE-2024-26147 in Helm
Summary
by MITRE • 02/22/2024
Helm is a package manager for Charts for Kubernetes. Versions prior to 3.14.2 contain an uninitialized variable vulnerability when Helm parses index and plugin yaml files missing expected content. When either an `index.yaml` file or a plugins `plugin.yaml` file were missing all metadata a panic would occur in Helm. In the Helm SDK, this is found when using the `LoadIndexFile` or `DownloadIndexFile` functions in the `repo` package or the `LoadDir` function in the `plugin` package. For the Helm client this impacts functions around adding a repository and all Helm functions if a malicious plugin is added as Helm inspects all known plugins on each invocation. This issue has been resolved in Helm v3.14.2. If a malicious plugin has been added which is causing all Helm client commands to panic, the malicious plugin can be manually removed from the filesystem. If using Helm SDK versions prior to 3.14.2, calls to affected functions can use `recover` to catch the panic.
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Analysis
by VulDB Data Team • 01/09/2025
The vulnerability identified as CVE-2024-26147 represents a critical uninitialized variable flaw within the Helm package manager for Kubernetes environments. This issue affects versions prior to 3142 and stems from insufficient validation during the parsing of index and plugin yaml files. When Helm encounters either an index.yaml file or a plugins plugin.yaml file that lacks expected metadata content, the system experiences a panic condition that can disrupt normal operations. The vulnerability manifests specifically within the Helm Software Development Kit where the LoadIndexFile and DownloadIndexFile functions in the repo package, along with the LoadDir function in the plugin package, fail to properly handle missing metadata scenarios. The technical implementation flaw creates an uninitialized variable state that leads to abrupt system termination during the parsing process.
The operational impact of this vulnerability extends significantly beyond simple parsing failures, particularly affecting Helm client functionality across entire Kubernetes environments. When a malicious plugin is introduced and added to the system, every Helm client command execution becomes vulnerable to panic conditions due to Helm's inspection of all known plugins during each invocation. This creates a persistent denial of service condition where legitimate users cannot execute standard Helm operations without encountering system crashes. The vulnerability particularly impacts repository management functions and all Helm commands, making it a critical concern for organizations relying on automated deployment pipelines. The panic condition occurs because the system attempts to access uninitialized memory locations when expected metadata fields are absent from the yaml configuration files, leading to unpredictable behavior and system instability.
The security implications of this vulnerability align with CWE-457: Use of Uninitialized Variable, which specifically addresses the dangerous practice of using variables that have not been properly initialized. From an adversarial perspective, this vulnerability maps to ATT&CK technique T1059.001: Command and Scripting Interpreter - PowerShell, where attackers could potentially leverage the panic conditions to disrupt operations or create confusion during system administration tasks. The vulnerability's exploitation requires minimal privileges and can be achieved through the simple addition of a malicious plugin to the filesystem, making it particularly concerning for environments where plugin management is not strictly controlled. Organizations implementing Helm in production environments face elevated risk of operational disruption and potential compromise of deployment automation workflows. The fix implemented in Helm v3.14.2 addresses the root cause by ensuring proper initialization of variables during yaml parsing operations and adding robust error handling to prevent panic conditions.
Mitigation strategies for this vulnerability involve immediate upgrade to Helm version 3.14.2 or later, which incorporates proper variable initialization and error handling mechanisms. For environments where immediate upgrading is not feasible, administrators should manually remove any malicious plugins from the filesystem to prevent the panic conditions from occurring during command execution. The Helm SDK provides a recovery mechanism through the use of recover functions when calling the affected functions, allowing applications to catch panic conditions and continue operation. Organizations should implement strict plugin management policies and conduct regular audits of installed plugins to prevent unauthorized additions. Additionally, monitoring systems should be configured to detect unusual panic conditions or system disruptions that may indicate exploitation attempts. The vulnerability serves as a reminder of the importance of proper input validation and error handling in package management systems, particularly those operating in critical infrastructure environments where reliability and stability are paramount for maintaining operational continuity.