CVE-2024-47901: Siemens InterMesh 7177 RCE Vulnerability

CVE-2024-47901 Overview

CVE-2024-47901 is a command injection vulnerability affecting Siemens InterMesh 7177 Hybrid 2.0 Subscriber and InterMesh 7707 Fire Subscriber devices. The web server on these devices fails to sanitize input parameters in specific HTTP GET requests, allowing operating system command execution. When chained with CVE-2024-47902, CVE-2024-47903, and CVE-2024-47904, an unauthenticated remote attacker can execute arbitrary code with root privileges. The flaw is tracked under [CWE-78] (Improper Neutralization of Special Elements used in an OS Command).

Critical Impact
Unauthenticated remote attackers can execute arbitrary OS commands on affected InterMesh subscriber devices, leading to full root compromise when combined with related vulnerabilities.

Affected Products

Siemens InterMesh 7177 Hybrid 2.0 Subscriber (All versions < V8.2.12)
Siemens InterMesh 7707 Fire Subscriber (All versions < V7.2.12, only when the IP interface is enabled)
Siemens InterMesh 7707 Fire Subscriber Firmware

Discovery Timeline

2024-10-23 - CVE-2024-47901 published to NVD
2024-10-30 - Last updated in NVD database

Technical Details for CVE-2024-47901

Vulnerability Analysis

The vulnerability resides in the embedded web server running on affected InterMesh subscriber devices. The server accepts parameters via HTTP GET requests and passes them to underlying operating system commands without sufficient sanitization. An attacker who reaches the web interface can inject shell metacharacters into vulnerable parameters and trigger command execution in the context of the web server process.

The flaw is independently exploitable for command execution. Chaining it with CVE-2024-47902, CVE-2024-47903, and CVE-2024-47904 elevates the impact to unauthenticated remote root code execution. The InterMesh 7707 Fire Subscriber is only exposed when its IP interface is enabled, which is not the default configuration. The InterMesh 7177 Hybrid 2.0 Subscriber is affected in all versions prior to V8.2.12.

Root Cause

The root cause is improper neutralization of special elements used in an OS command [CWE-78]. User-controlled input from GET request parameters is concatenated into shell command strings before execution, with no allowlist filtering or argument escaping. Shell metacharacters such as ;, |, &, and backticks pass through unaltered into the command interpreter.

Attack Vector

The vulnerability is reachable over the network with no authentication and no user interaction. An attacker sends a crafted HTTP GET request containing injected command syntax inside a vulnerable parameter. The web server then evaluates the payload in a shell context, executing the attacker-supplied commands on the device. When combined with the related CVEs, the resulting command execution runs with root privileges.

No verified public exploit code or proof-of-concept is currently available. The vulnerability mechanism is described in the Siemens Security Advisory SSA-333468.

Detection Methods for CVE-2024-47901

Indicators of Compromise

Unexpected outbound network connections originating from InterMesh subscriber devices, including reverse shell traffic
HTTP GET requests to the device web server containing shell metacharacters such as ;, |, &, $(), or URL-encoded equivalents %3B, %7C, %26
New or modified files on the device file system, particularly in writable directories used by the web server
Unauthorized processes spawned as child processes of the web server daemon

Detection Strategies

Inspect web server access logs on InterMesh devices for GET requests with suspicious parameter values containing command separators or encoded payloads
Monitor for anomalous CPU, memory, or network usage patterns on subscriber devices that diverge from normal radio gateway behavior
Deploy network IDS signatures targeting command injection patterns in HTTP traffic directed at InterMesh management interfaces

Monitoring Recommendations

Capture and centralize HTTP traffic to and from InterMesh device IP interfaces for retrospective analysis
Alert on any administrative or shell-related strings (/bin/sh, wget, curl, nc) appearing in URL query strings to device endpoints
Track firmware version inventory continuously to identify devices still running affected releases

How to Mitigate CVE-2024-47901

Immediate Actions Required

Update Siemens InterMesh 7177 Hybrid 2.0 Subscriber to version V8.2.12 or later
Update Siemens InterMesh 7707 Fire Subscriber to version V7.2.12 or later
For InterMesh 7707 Fire Subscriber, disable the IP interface unless it is operationally required, since the device is only exposed when this interface is enabled
Restrict network access to the device web server to trusted management networks only

Patch Information

Siemens has released fixed firmware versions addressing CVE-2024-47901. Apply InterMesh 7177 Hybrid 2.0 Subscriber V8.2.12 or InterMesh 7707 Fire Subscriber V7.2.12 as appropriate for the deployed model. Refer to the Siemens Security Advisory SSA-333468 for complete remediation details and download instructions.

Workarounds

Disable the IP interface on InterMesh 7707 Fire Subscriber devices where network management is not required
Place affected devices behind a firewall that blocks untrusted access to the management web interface
Apply strict network segmentation so InterMesh subscriber devices reside on isolated operational technology (OT) VLANs
Use access control lists to permit HTTP access only from authorized engineering workstations

bash

# Example firewall rule restricting access to the InterMesh web interface
# Allow only the management subnet to reach the device on TCP/80
iptables -A FORWARD -s 10.10.50.0/24 -d <intermesh_device_ip> -p tcp --dport 80 -j ACCEPT
iptables -A FORWARD -d <intermesh_device_ip> -p tcp --dport 80 -j DROP