CVE-2026-47359 in CloudStack
Summary
by MITRE • 08/21/2026
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') vulnerability in Apache CloudStack's NAS backup provider plugin. The addBackupRepository API (available since 4.20.0.0) and updateBackupRepository API (introduced in 4.22.0.0) accept unsanitized command options for the backup repository. A malicious operator account can exploit this to inject arbitrary commands that execute on the KVM hypervisor host when any account subsequently performs a backup restore.
This issue affects Apache CloudStack: from 4.20.0.0 through 4.20.3.0 and from 4.21.0.0 through 4.22.1.0.
Users are recommended to upgrade to version 4.20.3.1 or 4.22.1.1 or later, which fixes the issue.
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Analysis
by VulDB Data Team • 08/22/2026
The vulnerability identified as Improper Neutralization of Special Elements used in an OS Command represents a critical security flaw within Apache CloudStack's Network Attached Storage backup provider plugin. This specific class of weakness allows attackers to inject arbitrary operating system commands by manipulating input data that is subsequently passed to underlying shell interpreters without adequate sanitization or validation. The core technical failure lies in the handling of command options for the backup repository configuration, where special characters and metacharacters are not properly escaped or filtered before being incorporated into executable strings. This lack of proper neutralization creates a direct pathway for code execution on the host system, bypassing intended application-level access controls and exposing the underlying infrastructure to remote compromise.
The operational impact is particularly severe due to the specific APIs involved in this vulnerability: addBackupRepository and updateBackupRepository. The addBackupRepository API has been present since version 4.20.0.0, while the updateBackupRepository API was introduced later in version 4.22.0.0. Both endpoints accept user-supplied input for backup repository parameters that are directly concatenated into OS commands executed by the KVM hypervisor host. Although a malicious operator account may not have immediate root access to the hypervisor, they can leverage this flaw to inject payloads that execute with elevated privileges when any subsequent account performs a backup restore operation. This chain of events means that an attacker does not need direct shell access; instead, they only need permission to configure or modify backup repositories and trigger a restoration process, which serves as the execution vector for the injected commands.
From a classification perspective, this vulnerability aligns with CWE-78, Improper Neutralization of Special Elements used in an OS Command, commonly known as OS command injection. The attack scenario also maps closely to MITRE ATT&CK technique T1059, specifically subtechniques involving command and script interpreters such as sh or bash. By exploiting this flaw, an attacker can achieve arbitrary code execution on the KVM host, potentially leading to full system compromise, data exfiltration, lateral movement within the cloud environment, or denial of service through resource exhaustion. The severity is amplified by the fact that backup operations are often performed with high privileges, and the restoration process may involve complex script executions where input validation is frequently overlooked in favor of performance or compatibility considerations.
To mitigate this risk, organizations running affected versions must prioritize immediate patching. Apache CloudStack has released fixed versions 4.20.3.1 and 4.22.1.1 that address the improper neutralization issue by implementing robust input validation and command sanitization mechanisms within the backup provider plugin. Administrators should upgrade to these patched versions or any later release as soon as possible. In addition to upgrading, it is advisable to enforce strict role-based access control policies, ensuring that only trusted administrators can modify backup repository configurations. Monitoring logs for unusual patterns in backup restore operations and implementing network segmentation between management nodes and hypervisor hosts can further reduce the attack surface. Regular security audits of API endpoints and adherence to secure coding practices regarding command construction are essential preventive measures against similar injection vulnerabilities in cloud infrastructure software.