CVE-2015-5295 in OpenStack
Summary
by MITRE
The template-validate command in OpenStack Orchestration API (Heat) before 2015.1.3 (kilo) and 5.0.x before 5.0.1 (liberty) allows remote authenticated users to cause a denial of service (memory consumption) or determine the existence of local files via the resource type in a template, as demonstrated by file:///dev/zero.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 07/05/2022
The vulnerability CVE-2015-5295 affects the OpenStack Orchestration API component known as Heat, specifically within the template-validate command functionality. This issue exists in versions prior to 2015.1.3 (kilo release) and 5.0.1 (liberty release), representing a critical security flaw that impacts organizations utilizing OpenStack cloud infrastructure management services. The vulnerability stems from insufficient input validation and sanitization mechanisms within the template processing pipeline, creating a pathway for malicious actors to exploit the system through crafted template specifications.
The technical flaw manifests when the template-validate command processes resource type specifications within orchestration templates. Attackers can manipulate the resource type field to include malicious file paths such as file:///dev/zero, which causes the system to attempt to validate and process these references. This processing behavior leads to excessive memory consumption as the system tries to handle the malformed file references, ultimately resulting in resource exhaustion that can trigger denial of service conditions. The vulnerability also enables information disclosure by allowing attackers to probe local file system structures and determine the existence of specific files through the validation process.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to include potential information leakage that could aid attackers in further compromising the system. Remote authenticated users who can submit templates to the Heat service can leverage this flaw to consume excessive system resources, potentially causing legitimate operations to fail or become unavailable. The memory consumption aspect particularly affects systems with limited resources, making the impact more severe in constrained environments. Additionally, the file existence probing capability could reveal sensitive information about the underlying system configuration and file structure, providing attackers with valuable reconnaissance data for subsequent attacks.
Organizations should implement immediate mitigations including upgrading to patched versions of OpenStack Heat that address this vulnerability, typically found in the 2015.1.3 (kilo) and 5.0.1 (liberty) releases. Security configurations should enforce strict input validation on template submissions and implement resource limits to prevent excessive memory consumption during template validation processes. Network segmentation and access controls should be strengthened to limit who can submit templates to the Heat service, reducing the attack surface. The vulnerability aligns with CWE-20 Improper Input Validation and CWE-400 Uncontrolled Resource Consumption, representing a classic resource exhaustion attack vector that can be classified under the MITRE ATT&CK technique T1499.004 for resource exhaustion attacks.
This vulnerability demonstrates the importance of proper template validation and input sanitization in cloud orchestration systems, where malformed inputs can lead to cascading failures that impact entire cloud deployments. The flaw highlights the need for comprehensive security testing of infrastructure as code components and proper validation of all user-supplied inputs before processing them within cloud management systems. Organizations should also implement monitoring and alerting mechanisms to detect unusual memory consumption patterns that may indicate exploitation attempts of this vulnerability.