CVE-2019-17562 in CloudStack
Summary
by MITRE
A buffer overflow vulnerability has been found in the baremetal component of Apache CloudStack. This applies to all versions prior to 4.13.1. The vulnerability is due to the lack of validation of the mac parameter in baremetal virtual router. If you insert an arbitrary shell command into the mac parameter, v-router will process the command. For example: Normal: http://{GW}:10086/baremetal/provisiondone/{mac}, Abnormal: http://{GW}:10086/baremetal/provisiondone/#';whoami;#. Mitigation of this issue is an upgrade to Apache CloudStack 4.13.1.0 or beyond.
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Analysis
by VulDB Data Team • 05/15/2020
The CVE-2019-17562 vulnerability represents a critical buffer overflow flaw within the baremetal component of Apache CloudStack, affecting all versions prior to 4.13.1. This vulnerability specifically targets the virtual router implementation that handles baremetal provisioning workflows, creating a dangerous attack surface where malicious input can lead to arbitrary code execution. The flaw exists in the processing of the mac parameter within the baremetal provisioning endpoint, where insufficient input validation allows attackers to inject shell commands that get executed by the virtual router component. This vulnerability is particularly concerning as it operates at the network infrastructure level where baremetal provisioning occurs, potentially allowing attackers to gain unauthorized access to critical network components.
The technical implementation of this vulnerability stems from improper input sanitization within the baremetal virtual router's provisioning handler. When the system processes the mac parameter in the URL path, it fails to validate or sanitize the input before using it in command execution contexts. The vulnerability manifests when an attacker crafts a malicious URL with shell command injection syntax such as the example provided where '#';whoami;#' is embedded within the mac parameter. This allows the system to interpret and execute the injected commands as part of the provisioning process, effectively bypassing normal security controls. The flaw maps to CWE-121, Buffer Overflow in Stack, and CWE-78, Improper Neutralization of Special Elements used in a Command, indicating both the buffer overflow nature and the command injection vulnerability that enables the exploitation.
The operational impact of this vulnerability extends beyond simple command execution to potentially compromise entire baremetal provisioning workflows and the underlying network infrastructure. Attackers can leverage this vulnerability to execute arbitrary commands on the virtual router system, potentially gaining access to network credentials, modifying provisioning configurations, or even escalating privileges to full system control. The vulnerability affects the baremetal provisioning process which is critical for deploying physical servers within cloud environments, making it particularly dangerous for organizations relying on baremetal capabilities. According to ATT&CK framework, this vulnerability corresponds to T1059.001 Command and Scripting Interpreter: Shell Script and T1068 Exploitation for Privilege Escalation, demonstrating how the initial command injection can lead to broader system compromise. Organizations using Apache CloudStack versions prior to 4.13.1.0 face significant risk of unauthorized access and potential data breaches through this vector.
The mitigation strategy for CVE-2019-17562 requires immediate upgrade to Apache CloudStack version 4.13.1.0 or later, which includes proper input validation and sanitization for the mac parameter in the baremetal provisioning endpoint. Security administrators should also implement network segmentation and monitoring of the baremetal provisioning endpoints to detect anomalous traffic patterns that might indicate exploitation attempts. Additional protective measures include restricting access to the provisioning endpoints to trusted networks only and implementing web application firewalls to filter malicious input. Organizations should conduct thorough security assessments of their baremetal provisioning workflows and ensure that all components are updated to versions that have addressed this vulnerability. The vulnerability demonstrates the importance of input validation in network infrastructure components and highlights the need for robust security practices in cloud provisioning systems that handle sensitive operational data.