CVE-2017-4969 in Cloud Foundry
Summary
by MITRE
The Cloud Controller in Cloud Foundry cf-release versions prior to v255 allows authenticated developer users to exceed memory and disk quotas for tasks.
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Analysis
by VulDB Data Team • 09/19/2020
The vulnerability identified as CVE-2017-4969 resides within the Cloud Controller component of Cloud Foundry cf-release versions before v255, representing a critical authorization and resource management flaw that undermines the platform's core security controls. This issue specifically affects authenticated developer users who possess legitimate access credentials to the Cloud Foundry environment, creating a scenario where authorized personnel can exploit a design weakness to bypass imposed resource limitations. The Cloud Controller serves as the central management interface for Cloud Foundry operations, responsible for enforcing quotas, managing user permissions, and maintaining resource allocation boundaries across the platform's distributed architecture.
The technical flaw manifests through a privilege escalation mechanism that allows developers to manipulate task execution parameters beyond their allocated memory and disk constraints. When developers submit tasks through the Cloud Foundry API, the system should validate that these tasks remain within the user's assigned quota limits. However, the vulnerability enables malicious or unauthorized manipulation of these validation checks, permitting tasks to consume resources that exceed the predefined boundaries. This occurs due to insufficient input validation and inadequate enforcement of resource limits within the Cloud Controller's task processing logic. The flaw essentially creates a pathway where authenticated users can bypass the platform's resource governance mechanisms, potentially leading to resource exhaustion attacks against the underlying infrastructure.
The operational impact of this vulnerability extends beyond simple quota violations, creating significant risks to platform stability, performance, and security posture. Attackers exploiting this vulnerability can consume excessive memory and disk resources, potentially causing denial of service conditions for other users within the same organization or even compromising the entire Cloud Foundry deployment. The ability to exceed resource quotas enables exploitation of resource starvation attacks that can affect not only the targeted user's tasks but also impact the performance of other applications running on the same platform. This vulnerability directly impacts the principle of least privilege and resource isolation that Cloud Foundry aims to enforce, creating potential for cascading failures and unauthorized resource consumption that can lead to service disruption and data integrity concerns.
Organizations utilizing Cloud Foundry cf-release versions prior to v255 should prioritize immediate remediation through patching to address this vulnerability, as it represents a fundamental weakness in the platform's access control and resource management systems. The recommended mitigation involves upgrading to cf-release version v255 or later, which includes proper validation mechanisms and enhanced quota enforcement controls. Security teams should also implement additional monitoring and alerting for unusual resource consumption patterns, particularly when tasks exceed normal operational parameters. This vulnerability aligns with CWE-284 (Improper Access Control) and CWE-119 (Improper Access Control) categories, reflecting weaknesses in authorization enforcement and resource management. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and resource hijacking, where adversaries leverage legitimate access to consume excessive system resources. The issue also demonstrates a failure in the principle of resource isolation, where proper boundaries between user accounts and system resources are not maintained, potentially enabling broader exploitation scenarios that could compromise the overall platform security architecture.