Executive brief
Apache CloudStack is an open-source cloud management platform that allows operators to manage virtual infrastructure and backups. A command injection vulnerability in the NAS backup provider plugin allows a malicious operator to inject arbitrary commands that execute on KVM hypervisor hosts during backup restore operations, potentially compromising the underlying infrastructure.
Technical details
An OS command injection vulnerability exists in Apache CloudStack's NAS backup provider plugin in the addBackupRepository (4.20.0.0+) and updateBackupRepository (4.21.0.0+) APIs. These APIs accept unsanitized command options passed directly to backup repository configuration without proper input validation or escaping. An attacker with operator privileges can inject shell metacharacters into these parameters to execute arbitrary commands on the KVM hypervisor when any account performs a backup restore operation. The vulnerability requires operator-level access but allows full command execution on the underlying hypervisor host, compromising system integrity and potentially affecting all hosted virtual machines.
Affected products
- Apache CloudStack 4.20.0.0 through 4.20.3.0, 4.21.0.0 through 4.22.1.0
Timeline
- 2026-08-21: disclosed
- 2026-08-21: patched: Fixed in versions 4.20.3.1, 4.22.1.1, and later