CVE-2015-4017 in Salt
Summary
by MITRE
Salt before 2014.7.6 does not verify certificates when connecting via the aliyun, proxmox, and splunk modules.
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Analysis
by VulDB Data Team • 11/10/2019
The vulnerability identified as CVE-2015-4017 affects the Salt configuration management system prior to version 2014.7.6 and specifically impacts three cloud and monitoring modules including aliyun, proxmox, and splunk. This represents a critical security flaw that undermines the integrity of certificate verification processes during remote connections, potentially exposing systems to man-in-the-middle attacks and unauthorized access. The issue stems from the absence of proper SSL/TLS certificate validation mechanisms within these modules, creating a significant attack surface for malicious actors who could intercept or manipulate communications between Salt masters and remote services.
The technical flaw manifests in the improper handling of secure communication channels through which Salt interacts with cloud infrastructure providers and monitoring systems. When Salt attempts to establish connections using the affected aliyun, proxmox, or splunk modules, it fails to validate the authenticity of server certificates presented during the SSL/TLS handshake process. This omission allows attackers to perform certificate pinning attacks by presenting fake certificates that would otherwise be rejected by proper verification mechanisms. The vulnerability directly relates to CWE-295 which addresses improper certificate validation and can be categorized under ATT&CK technique T1071.004 for application layer protocol: DNS, representing how attackers might exploit weakened certificate validation to establish unauthorized connections.
The operational impact of this vulnerability extends beyond simple communication failures, potentially enabling attackers to gain unauthorized access to cloud resources managed by Salt or to manipulate monitoring data collected through the splunk module. Organizations using Salt for infrastructure automation and monitoring could face severe consequences including data exfiltration, system compromise, and unauthorized modifications to cloud resources managed through the aliyun and proxmox modules. The risk is particularly elevated in environments where Salt is used to manage critical infrastructure components, as attackers could exploit this weakness to establish persistent access or disrupt service availability.
Mitigation strategies for CVE-2015-4017 require immediate implementation of version updates to Salt 2014.7.6 or later, which includes proper certificate validation mechanisms for the affected modules. Organizations should also implement additional network-level security controls such as certificate pinning, network segmentation, and monitoring for unusual communication patterns that might indicate certificate validation bypass attempts. The fix addresses the root cause by implementing proper SSL/TLS certificate validation procedures that align with industry standards and best practices for secure remote communication. Security teams should conduct comprehensive vulnerability assessments to identify any systems still running affected Salt versions and ensure that all certificate validation mechanisms are properly configured and tested. This remediation aligns with security frameworks that emphasize the importance of certificate validation as a fundamental security control for preventing unauthorized access to critical infrastructure components.