CVE-2017-2296 in Puppet Enterprise
Summary
by MITRE
In Puppet Enterprise 2017.1.x and 2017.2.1, using specially formatted strings with certain formatting characters as Classifier node group names or RBAC role display names causes errors, effectively causing a DOS to the service. This was resolved in Puppet Enterprise 2017.2.2.
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Analysis
by VulDB Data Team • 12/31/2019
The vulnerability described in CVE-2017-2296 represents a denial of service flaw affecting Puppet Enterprise versions 2017.1.x and 2017.2.1, specifically targeting the Classifier component and Role-Based Access Control system. This issue arises from insufficient input validation when processing specially crafted strings containing specific formatting characters that are used as node group names or role display names within the Puppet Enterprise management framework. The flaw demonstrates characteristics consistent with CWE-170, which addresses improper handling of string termination or encoding, particularly in scenarios involving user-supplied input that is not properly sanitized or validated.
The technical implementation of this vulnerability exploits the way Puppet Enterprise processes and validates user-provided identifiers during the classification and access control operations. When maliciously formatted strings containing special characters are submitted as node group names or RBAC role display names, the underlying parsing mechanisms fail to handle these inputs gracefully, resulting in service disruption rather than proper error handling. This behavior creates an exploitable condition where an attacker can deliberately craft input that triggers internal processing errors, leading to complete service unavailability for legitimate users attempting to manage their Puppet infrastructure.
The operational impact of this vulnerability extends beyond simple service disruption, as it affects critical infrastructure management capabilities within Puppet Enterprise environments. Organizations relying on Puppet for configuration management and automation face potential operational downtime when this vulnerability is exploited, particularly in production environments where continuous service availability is essential. The flaw essentially allows an attacker to render the Puppet Enterprise Classifier and RBAC systems unusable, preventing authorized administrators from managing node groups or controlling access permissions, which fundamentally undermines the security and management capabilities of the platform.
Mitigation strategies for this vulnerability require immediate deployment of Puppet Enterprise version 2017.2.2, which contains the necessary patches addressing the input validation flaws. Organizations should also implement additional monitoring and input sanitization measures within their Puppet infrastructure, including validating all user-provided identifiers before they are processed by the system. From an att&ck perspective, this vulnerability aligns with techniques involving service disruption and denial of service attacks, specifically targeting the availability component of the CIA triad. Security teams should consider implementing network segmentation and access controls to limit exposure to this type of vulnerability, while also ensuring comprehensive testing of input validation mechanisms within their Puppet deployments to prevent similar issues from arising in other components of their infrastructure.