CVE-2024-38346: Apache CloudStack RCE Vulnerability

CVE-2024-38346 Overview

CVE-2024-38346 is a critical command injection vulnerability in Apache CloudStack that allows unauthenticated remote code execution. The CloudStack cluster service runs on an unauthenticated port (default 9090) that can be exploited to execute arbitrary commands on targeted hypervisors and CloudStack management server hosts. Several commands exposed through this service were found to have command injection vulnerabilities that enable arbitrary code execution via agents on the hosts, which may run as a privileged user.

An attacker who can reach the cluster service on the unauthenticated port can exploit this vulnerability to perform remote code execution on CloudStack managed hosts, resulting in complete compromise of the confidentiality, integrity, and availability of CloudStack managed infrastructure.

Critical Impact

Complete compromise of CloudStack managed infrastructure through unauthenticated remote code execution, affecting all managed hypervisors and management server hosts.

Affected Products

• Apache CloudStack versions prior to 4.18.2.1
• Apache CloudStack versions prior to 4.19.0.2

Discovery Timeline

• July 5, 2024 - CVE-2024-38346 published to NVD
• February 13, 2025 - Last updated in NVD database

Technical Details for CVE-2024-38346

Vulnerability Analysis

This vulnerability stems from inadequate access controls on the CloudStack cluster service combined with command injection flaws in the service's command handling. The cluster service, which facilitates communication between CloudStack management servers and hypervisor hosts, listens on port 9090 by default without requiring authentication.

The service exposes several commands that can be invoked by any network-accessible client. Critical command injection vulnerabilities exist within these exposed functions, allowing attackers to inject and execute arbitrary operating system commands. Because the agent processes on managed hosts often run with elevated privileges (such as root), successful exploitation grants the attacker privileged access to the underlying systems.

The attack surface is particularly dangerous in environments where the cluster service port is exposed to untrusted networks or the broader internet, as no credentials are required to interact with the vulnerable service.

Root Cause

The root cause is twofold: first, the cluster service (port 9090) lacks authentication mechanisms, allowing any network-accessible client to send commands. Second, improper input validation and sanitization in the command processing logic creates command injection vulnerabilities (CWE-94: Improper Control of Generation of Code). User-controllable input is passed to system commands without adequate sanitization, enabling shell metacharacter injection.

Attack Vector

The attack vector is network-based and requires no authentication or user interaction. An attacker with network access to port 9090 on a CloudStack management server can:

1. Connect directly to the unauthenticated cluster service
2. Send crafted requests containing malicious command injection payloads
3. Achieve arbitrary command execution on the management server or connected hypervisor hosts
4. Escalate access to compromise the entire CloudStack managed infrastructure

The vulnerability allows complete remote code execution without any authentication, making it trivially exploitable once the cluster service port is reachable. For detailed technical information about the vulnerability mechanism, refer to the Apache CloudStack Security Advisory and the Openwall OSS Security Discussion.

Detection Methods for CVE-2024-38346

Indicators of Compromise

• Unexpected connections to port 9090 from external or untrusted IP addresses
• Unusual process spawning or command execution on CloudStack management servers or hypervisor hosts
• Suspicious shell commands or script executions initiated by the CloudStack agent process
• Log entries showing malformed or unusual requests to the cluster service

Detection Strategies

• Monitor network traffic to port 9090 for connections from unauthorized sources
• Implement IDS/IPS rules to detect command injection patterns in cluster service traffic
• Enable and review CloudStack management server logs for anomalous cluster service requests
• Deploy endpoint detection to alert on unexpected child processes spawned by CloudStack services

Monitoring Recommendations

• Establish baseline network behavior and alert on deviations involving port 9090 traffic
• Configure SIEM rules to correlate cluster service access with subsequent privileged command execution
• Regularly audit firewall rules to ensure port 9090 is restricted to trusted management server peers only
• Implement file integrity monitoring on CloudStack management server and hypervisor hosts

How to Mitigate CVE-2024-38346

Immediate Actions Required

• Restrict network access to port 9090 using firewall rules to allow only trusted CloudStack management server peers
• Audit network configurations to ensure the cluster service is not exposed to untrusted networks or the internet
• Upgrade Apache CloudStack to version 4.18.2.1, 4.19.0.2, or later immediately
• Review system logs for any signs of prior exploitation attempts

Patch Information

Apache CloudStack has released security patches addressing this vulnerability. Users should upgrade to version 4.18.2.1 or 4.19.0.2 or later. Patch details and upgrade instructions are available in the Apache CloudStack Security Advisory and the ShapeBlue Security Advisory.

Workarounds

• Implement firewall rules to restrict port 9090 access exclusively to peer CloudStack management server hosts
• Deploy network segmentation to isolate CloudStack management infrastructure from untrusted networks
• Use host-based firewalls (iptables/firewalld) as an additional layer of protection on each management server
• Consider deploying a VPN or private network for inter-management-server communication if upgrading is delayed

# Example iptables rules to restrict cluster service access
# Allow only specific peer management server IPs
iptables -A INPUT -p tcp --dport 9090 -s <PEER_MGMT_SERVER_IP_1> -j ACCEPT
iptables -A INPUT -p tcp --dport 9090 -s <PEER_MGMT_SERVER_IP_2> -j ACCEPT
# Drop all other traffic to port 9090
iptables -A INPUT -p tcp --dport 9090 -j DROP