CVE-2026-56413 Overview
CVE-2026-56413 is a command injection vulnerability [CWE-78] in the StoneFly Storage Concentrator (SC) and Storage Concentrator Virtual Machine (SCVM) products. The flaw resides in the ms_service.pl service, which listens on TCP port 9000 by default and accepts custom network packets to perform device actions. An unauthenticated remote attacker can send a crafted packet containing a malicious payload that is processed without adequate sanitization. Successful exploitation results in arbitrary command execution with root-level privileges on the affected storage appliance.
Critical Impact
Unauthenticated remote attackers can execute arbitrary operating system commands as root on affected Storage Concentrator devices, leading to full device compromise, data theft, and lateral movement into connected storage networks.
Affected Products
- StoneFly Storage Concentrator (SC)
- StoneFly Storage Concentrator Virtual Machine (SCVM)
- Devices exposing ms_service.pl on TCP port 9000
Discovery Timeline
- 2026-06-30 - CVE-2026-56413 published to the National Vulnerability Database
- 2026-07-01 - Last updated in NVD database
Technical Details for CVE-2026-56413
Vulnerability Analysis
The Storage Concentrator platform exposes a Perl-based control service, ms_service.pl, on TCP port 9000. The service accepts custom network packets that instruct the device to perform administrative actions on the underlying operating system. The service parses attacker-controlled fields from these packets and passes them into shell command invocations without adequate validation, escaping, or use of safe process-execution primitives.
Because the service runs as root and does not require authentication for the affected code path, any host that can reach port 9000 can drive command execution end to end. The exploitation path traverses the network from an unauthenticated source directly to a privileged shell, with no user interaction required.
Root Cause
The root cause is improper neutralization of special elements used in an operating system command [CWE-78]. User-supplied data delivered inside the custom packet format is concatenated into shell strings executed by the Perl service. Metacharacters such as ;, |, &, backticks, and $(...) are not stripped or escaped, allowing attacker-supplied fragments to break out of the intended command context and execute arbitrary commands.
Attack Vector
Exploitation requires only network access to TCP port 9000 on a vulnerable Storage Concentrator or SCVM instance. The attacker constructs a packet conforming to the expected ms_service protocol and embeds shell metacharacters within a field that reaches the command interpreter. Because the vulnerable process runs as root, injected commands inherit full system privileges and can read or modify any file, deploy persistence, exfiltrate storage contents, or pivot into adjacent storage and management networks.
No verified public proof-of-concept code is available. Refer to the CISA ICS Advisory ICSA-26-181-06 and the GitHub CSAF JSON Resource for the authoritative technical description.
Detection Methods for CVE-2026-56413
Indicators of Compromise
- Unexpected inbound TCP connections to port 9000 on Storage Concentrator or SCVM appliances from untrusted networks.
- Child processes of perl or ms_service.pl spawning shell binaries such as /bin/sh, /bin/bash, nc, curl, or wget.
- New or modified files under /root, /tmp, /var/tmp, or persistence locations such as /etc/cron.d/ and /etc/systemd/system/.
- Outbound connections from the appliance to unknown IP addresses following inbound traffic on port 9000.
Detection Strategies
- Monitor network flow data for connections to TCP 9000 originating outside the storage management VLAN.
- Inspect payloads destined for ms_service.pl for shell metacharacters (;, |, `, $(, &&) inside protocol fields.
- Alert on process ancestry where a Perl interpreter spawns interactive shells or network utilities on storage appliances.
Monitoring Recommendations
- Enable verbose logging on the ms_service daemon and forward logs to a centralized SIEM for correlation.
- Baseline normal administrative traffic to port 9000 and alert on deviations in source, frequency, or payload size.
- Track file integrity on the appliance root filesystem, focusing on startup scripts and cron directories.
How to Mitigate CVE-2026-56413
Immediate Actions Required
- Restrict TCP port 9000 to a dedicated management network using firewall or ACL rules and block all internet-facing exposure.
- Contact StoneFly through the Stonefly Contact Page to obtain patched firmware and coordinated remediation guidance.
- Audit appliance logs, running processes, and filesystem changes for signs of prior exploitation.
- Rotate credentials and API keys that were stored on or accessible from the affected appliance.
Patch Information
At the time of publication, no fixed version was enumerated in the NVD entry. Operators should consult the CISA ICS Advisory ICSA-26-181-06 for the current vendor remediation status and apply vendor-supplied firmware updates as soon as they are made available.
Workarounds
- Place Storage Concentrator and SCVM appliances behind a jump host and require VPN or bastion access for management traffic.
- Disable the ms_service.pl listener on port 9000 if the operational workflow permits, or bind it to a loopback interface.
- Deploy network segmentation to isolate storage appliances from general enterprise, guest, and internet-routable networks.
# Configuration example: restrict TCP port 9000 to a management subnet using iptables
iptables -A INPUT -p tcp --dport 9000 -s 10.10.20.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 9000 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
