CVE-2025-67601 in Rancher
Summary
by MITRE • 02/25/2026
A vulnerability has been identified within Rancher Manager, where using self-signed CA certificates and passing the -skip-verify flag to the Rancher CLI login command without also passing the –cacert flag results in the CLI attempting to fetch CA certificates stored in Rancher’s setting cacerts.
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Analysis
by VulDB Data Team • 03/03/2026
This vulnerability exists within Rancher Manager's command line interface authentication mechanism, specifically when handling certificate validation during the login process. The issue manifests when users attempt to authenticate using self-signed certificates while employing the -skip-verify flag without simultaneously providing the --cacert flag. This configuration creates a dangerous operational scenario where the CLI system attempts to retrieve CA certificates from Rancher's internal cacerts setting, potentially exposing the system to man-in-the-middle attacks or certificate validation bypasses.
The technical flaw stems from improper certificate validation logic within the Rancher CLI implementation. When the -skip-verify flag is used without --cacert, the system fails to properly validate the certificate chain and instead attempts to fetch certificates from the Rancher manager's internal certificate store. This behavior violates fundamental security principles of certificate validation and creates an attack surface where malicious actors could potentially manipulate the certificate retrieval process. The vulnerability aligns with CWE-295 which addresses improper certificate validation and CWE-310 which covers cryptographic issues related to certificate handling. From an ATT&CK perspective, this vulnerability maps to T1566.001 (Phishing: Spearphishing Attachment) and T1071.004 (Application Layer Protocol: DNS) as it could enable attackers to establish unauthorized connections or intercept communications through compromised certificate validation.
The operational impact of this vulnerability extends beyond simple authentication failures to create significant security risks for organizations using Rancher Manager. When the CLI attempts to fetch certificates from Rancher's internal settings, it creates opportunities for credential theft, unauthorized access to containerized environments, and potential privilege escalation within the Rancher management plane. The vulnerability particularly affects environments where self-signed certificates are commonly used, such as development or testing environments, but can also impact production systems if administrators are not properly trained on certificate management practices. Organizations may experience unauthorized access to their container orchestration platforms, leading to potential data breaches, service disruption, and compliance violations.
Mitigation strategies should focus on proper certificate management practices and CLI usage protocols. Administrators must ensure that all certificate validation parameters are properly configured when using the Rancher CLI, specifically requiring the use of both -skip-verify and --cacert flags together or implementing proper certificate validation through trusted certificate authorities. Organizations should establish strict operational procedures for certificate management, including regular certificate rotation policies and automated certificate validation checks. The implementation of security awareness training for system administrators is crucial to prevent improper CLI usage patterns. Additionally, organizations should consider implementing network segmentation and monitoring solutions to detect anomalous certificate retrieval behaviors, as well as regular security audits to ensure proper certificate handling practices are maintained. The vulnerability highlights the importance of following security best practices for certificate management as outlined in NIST SP 800-57 and ISO/IEC 15408 standards, particularly regarding the proper validation of cryptographic certificates and the implementation of secure communication protocols.