CVE-2020-15187 is a vulnerability identified in Helm, a widely used package manager for Kubernetes. The issue affects Helm versions prior to 2.16.11 and 3.3.2. The vulnerability arises from the use of multiple resources with duplicate identifiers within Helm plugins. Specifically, if a plugin contains duplicate entries, the last entry is always used, which can be exploited by an attacker to modify a plugin's install hooks. This modification can lead to local code execution under certain conditions. The attack scenario requires that the attacker has write access to the git repository or the plugin archive (.tgz) at the time it is being downloaded. This situation can occur during a man-in-the-middle (MITM) attack if the plugin is downloaded over an insecure, non-SSL connection. By exploiting this vulnerability, an attacker can lower the level of access needed to execute malicious code locally through the compromised plugin. The vulnerability is classified under CWE-694 (Use of Multiple Resources with Duplicate Identifier) and CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component). The issue has been addressed in Helm versions 2.16.11 and 3.3.2 by ensuring proper handling of duplicate entries and enforcing secure plugin installation protocols. The CVSS v3.1 base score is 3.0, indicating a low severity level, with the vector highlighting that the attack requires network access, high attack complexity, low privileges, and user interaction, with no impact on confidentiality but some impact on integrity and no impact on availability.

For European organizations, the impact of this vulnerability is primarily related to the integrity of Kubernetes deployments managed via Helm. If exploited, an attacker could execute arbitrary code locally by modifying plugin install hooks, potentially leading to unauthorized changes in the Kubernetes environment. This could compromise deployment processes, introduce malicious configurations, or disrupt application behavior. However, the requirement for write access to the plugin source or archive and the need for a non-SSL connection during plugin installation reduce the likelihood of exploitation. Organizations relying heavily on Helm for Kubernetes package management, especially those using older versions or downloading plugins over unsecured channels, are at risk. The vulnerability could be leveraged in targeted attacks, particularly in environments where internal network security is weak or where supply chain attacks are a concern. The impact on confidentiality is minimal, but the integrity of deployment pipelines and the trustworthiness of installed plugins could be compromised, potentially leading to further lateral movement or persistence within the infrastructure.

To mitigate this vulnerability, European organizations should: 1) Upgrade Helm to versions 2.16.11 or later, or 3.3.2 or later, where the vulnerability is patched. 2) Ensure that all Helm plugins are installed exclusively over secure channels such as HTTPS or other SSL/TLS-encrypted protocols to prevent MITM attacks during plugin download. 3) Implement strict access controls on git repositories and plugin archives to prevent unauthorized write access. 4) Employ integrity verification mechanisms such as checksums or digital signatures for plugins before installation to detect tampering. 5) Monitor network traffic for unusual activity that could indicate MITM attempts or unauthorized access to plugin sources. 6) Educate DevOps and security teams about the risks of using outdated Helm versions and insecure plugin installation methods. 7) Integrate automated scanning tools in CI/CD pipelines to detect usage of vulnerable Helm versions or insecure plugin sources.