CVE-2026-61400 in CloudStack
Summary
by MITRE • 08/21/2026
Improper Neutralization of Special Elements used in a Command ('Command Injection') vulnerability in Apache CloudStack's run and get diagnostics functionality for the system VMs and virtual routers.
An authenticated user holding the permissions required to invoke either `getDiagnosticsData` or `runDiagnostics` can achieve arbitrary command execution on the system VM and/or Virtual Router instances, with commands running as root (or as the diagnostics-process user, at minimum). This represents a full compromise of the affected instance and, depending on network segmentation, may provide a foothold for lateral movement within the CloudStack-managed infrastructure, including access to guest network traffic handled by the compromised Virtual Router.
The getDiagnosticsData and runDiagnostics APIs are restricted to only Admin role accounts by default.
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 • 08/24/2026
The vulnerability identified as Improper Neutralization of Special Elements used in a Command represents a critical security flaw within Apache CloudStack versions ranging from 4.20.0.0 through 4.20.3.0 and from 4.21.0.0 through 4.22.1.0. This specific weakness is located in the system that handles diagnostics for system VMs and virtual routers, specifically within the getDiagnosticsData and runDiagnostics API endpoints. The core technical flaw stems from a failure to properly sanitize or validate user-supplied input before it is incorporated into operating system commands executed by the backend processes. When an authenticated user invokes these APIs with permissions sufficient to trigger diagnostic operations, the application constructs shell commands dynamically without adequately escaping special characters or controlling command arguments. This lack of rigorous input validation allows an attacker to inject arbitrary metacharacters that alter the intended logic of the command string, effectively enabling Command Injection as defined by CWE-78 in the Common Weakness Enumeration standard.
The operational impact of this vulnerability is severe due to the elevated privileges associated with the affected components. An authenticated user who holds the necessary permissions can achieve arbitrary command execution on the system VM and virtual router instances. The commands executed through this injection typically run as root or, at a minimum, as the diagnostics-process user, which grants significant control over the underlying operating system environment. This results in a full compromise of the affected instance, allowing the attacker to read sensitive configuration files, modify system settings, install malicious software, or exfiltrate data directly from the hypervisor management layer. The severity is further amplified by the fact that these components are central to cloud infrastructure operations, meaning the breach extends beyond a single isolated process into critical network and compute resources managed by CloudStack.
Beyond immediate host compromise, this vulnerability poses significant risks for lateral movement within the broader CloudStack-managed infrastructure. Virtual routers often handle routing and firewalling duties for guest networks, acting as gateways between tenant virtual machines and external networks or other internal segments. By compromising a virtual router through command injection, an attacker can potentially intercept, modify, or redirect network traffic destined for or originating from these guest VMs. This capability facilitates man-in-the-middle attacks, credential harvesting, and unauthorized access to isolated network zones that might otherwise be protected by segmentation policies enforced at the router level. Consequently, this flaw undermines the isolation guarantees provided by the cloud platform, allowing a breach in one area to cascade into widespread infrastructure compromise depending on the specific network topology and security controls in place.
In terms of threat modeling, this vulnerability aligns with MITRE ATT&CK techniques related to Command and Scripting Interpreter abuse, specifically those involving remote command execution via API endpoints or service exploitation. The attack vector requires authentication, which classifies it as an authenticated insider threat or a result of compromised credentials rather than a purely external unauthenticated exploit. However, given that the getDiagnosticsData and runDiagnostics APIs are restricted to Admin role accounts by default in standard configurations, the primary risk involves privilege escalation from lower-level admin roles or credential theft targeting high-privilege administrative accounts. Attackers who gain access to these credentials can leverage this flaw to pivot into deeper layers of the cloud environment, making it a critical concern for organizations relying on Apache CloudStack for their infrastructure-as-a-service deployments.
To mitigate this risk, users are strongly advised to upgrade immediately to version 4.20.3.1 or 4.22.1.1 and later releases where the input validation logic has been corrected to properly neutralize special elements before command execution. In addition to patching, organizations should enforce strict access controls on diagnostic APIs, ensuring that only essential personnel have permissions to invoke these functions. Network segmentation strategies should be reviewed to limit the blast radius of a potential virtual router compromise, and monitoring solutions should be configured to detect anomalous command executions or unusual network traffic patterns originating from system VMs and routers. Regular audits of administrative account activity can also help in identifying unauthorized attempts to exploit this vulnerability before significant damage occurs.