CVE-2025-7342 is a high-severity vulnerability identified in the Kubernetes Image Builder project, specifically affecting the Windows image build process when using Nutanix or VMware OVA providers. The vulnerability arises from the use of hard-coded default credentials that are enabled during the image build phase. These credentials grant root-level access and are intended to be disabled once the build completes. However, if an attacker gains access to the build virtual machine (VM) during the image creation process, they can exploit these credentials to modify the image, embedding malicious code or backdoors before the image is finalized and deployed. This vulnerability is categorized under CWE-798, which concerns the use of hard-coded credentials, a known security anti-pattern that can lead to unauthorized access. The attack vector is network-based (AV:N) but requires high attack complexity (AC:H), no privileges (PR:N), and user interaction (UI:R). The scope remains unchanged (S:U), but the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H). Importantly, only Kubernetes clusters using VM images built via this Image Builder process with the affected providers are at risk, and exploitation requires access to the build environment during the build process. There are no known exploits in the wild as of the publication date, and no patches have been linked yet. This vulnerability highlights the risk in the build pipeline, where compromise can lead to persistent and widespread impact once the compromised images are deployed across clusters.

For European organizations, this vulnerability poses a significant risk primarily to those leveraging Kubernetes clusters with Windows nodes built using the Kubernetes Image Builder and Nutanix or VMware OVA providers. Compromise of the build VM can lead to the insertion of malicious code or backdoors into VM images, which, once deployed, can provide attackers with root-level access across multiple nodes in production environments. This can result in data breaches, lateral movement within networks, disruption of services, and potential compromise of sensitive or regulated data. Given the high reliance on Kubernetes for cloud-native applications and the widespread use of VMware and Nutanix virtualization platforms in European enterprises, the risk is non-trivial. Additionally, the requirement for attacker access to the build VM means that organizations with less secure build environments or insufficient network segmentation are at greater risk. The impact extends beyond individual clusters, as compromised images can propagate through CI/CD pipelines and affect multiple deployments, amplifying the threat. This vulnerability also raises concerns for compliance with European data protection regulations, as unauthorized access and data integrity violations could lead to regulatory penalties.

To mitigate this vulnerability, European organizations should implement strict access controls and monitoring around their Kubernetes Image Builder environments, especially the build VMs used for Windows image creation with Nutanix or VMware OVA providers. Network segmentation should isolate build environments from general network access to reduce the risk of unauthorized access. Employing multi-factor authentication and limiting user interaction during the build process can further reduce exposure. Organizations should audit their build pipelines to detect any use of default or hard-coded credentials and replace them with secure, dynamically generated credentials or secrets management solutions. Continuous monitoring and integrity verification of images post-build can help detect unauthorized modifications. Until an official patch is released, consider alternative image building methods or providers that do not exhibit this vulnerability. Additionally, implementing runtime security controls on deployed clusters can help detect and mitigate the impact of compromised images. Regular security training for personnel managing build environments is also recommended to prevent social engineering or accidental exposure.