CVE-2024-32740 Overview
A hardcoded credentials vulnerability has been identified in Siemens SIMATIC CN 4100, affecting all versions prior to V3.0. The affected device contains undocumented users and credentials that could allow an attacker to compromise the device locally or over the network. This vulnerability represents a significant security risk for industrial control system environments where SIMATIC CN 4100 devices are deployed.
Critical Impact
Attackers can leverage undocumented hardcoded credentials to gain unauthorized access to SIMATIC CN 4100 devices, potentially compromising confidentiality, integrity, and availability of industrial control systems.
Affected Products
- Siemens SIMATIC CN 4100 Firmware (All versions < V3.0)
- Siemens SIMATIC CN 4100 Hardware
Discovery Timeline
- 2024-05-14 - CVE-2024-32740 published to NVD
- 2025-08-20 - Last updated in NVD database
Technical Details for CVE-2024-32740
Vulnerability Analysis
This vulnerability falls under CWE-798 (Use of Hard-coded Credentials), a common security weakness where authentication credentials are embedded directly in firmware or software. The SIMATIC CN 4100, an industrial communication node used in Siemens automation environments, contains undocumented user accounts with static credentials that cannot be changed or disabled by administrators.
The presence of hardcoded credentials in industrial control system (ICS) devices is particularly dangerous because these devices often operate in sensitive environments controlling critical infrastructure. An attacker who discovers these credentials can authenticate to the device without needing to exploit any additional vulnerabilities.
Root Cause
The root cause of this vulnerability is the inclusion of undocumented user accounts with hardcoded credentials within the SIMATIC CN 4100 firmware. These credentials appear to have been left in the production firmware, possibly from development or debugging purposes. The lack of documentation for these accounts means administrators have no way to know they exist, much less disable or change them.
Attack Vector
This vulnerability is exploitable over the network without requiring any user interaction or prior authentication. An attacker with network access to a vulnerable SIMATIC CN 4100 device can use the hardcoded credentials to authenticate and gain full access to the device. The attack can be performed remotely, making it particularly concerning for devices exposed to untrusted networks or the internet.
The exploitation process involves:
- Network reconnaissance to identify SIMATIC CN 4100 devices
- Attempting authentication using the undocumented credentials
- Upon successful authentication, gaining full access to device configuration and functionality
- Potential lateral movement to other connected industrial systems
Detection Methods for CVE-2024-32740
Indicators of Compromise
- Unexpected authentication attempts or successful logins to SIMATIC CN 4100 devices from unknown sources
- Configuration changes to SIMATIC CN 4100 devices that were not authorized by administrators
- Network traffic anomalies involving communication with SIMATIC CN 4100 management interfaces
- Unauthorized user sessions active on the device outside normal operational hours
Detection Strategies
- Implement network monitoring to detect authentication attempts to SIMATIC CN 4100 devices, particularly from external or unauthorized IP addresses
- Deploy intrusion detection systems (IDS) with signatures for known SIMATIC device authentication protocols
- Review authentication logs on SIMATIC CN 4100 devices for any unusual login patterns or access from unexpected sources
- Utilize SentinelOne Singularity to monitor for suspicious network connections and authentication behaviors targeting industrial devices
Monitoring Recommendations
- Enable comprehensive logging on all SIMATIC CN 4100 devices and forward logs to a centralized SIEM
- Monitor network segments containing industrial control devices for any unauthorized access attempts
- Implement network segmentation to isolate SIMATIC CN 4100 devices and control access through firewalls with logging enabled
- Regularly audit active sessions and user accounts on all industrial control devices
How to Mitigate CVE-2024-32740
Immediate Actions Required
- Upgrade all SIMATIC CN 4100 devices to firmware version V3.0 or later immediately
- Isolate vulnerable SIMATIC CN 4100 devices on segmented network zones with strict access controls until patching is complete
- Review and restrict network access to SIMATIC CN 4100 management interfaces to authorized administrative workstations only
- Audit authentication logs on affected devices for any signs of unauthorized access
Patch Information
Siemens has addressed this vulnerability in SIMATIC CN 4100 firmware version V3.0. Organizations should obtain the updated firmware from Siemens and apply it following their change management procedures. Detailed patch information is available in the Siemens Security Advisory SSA-273900.
Workarounds
- Implement strict network segmentation to prevent unauthorized access to SIMATIC CN 4100 devices from untrusted networks
- Deploy firewall rules to restrict access to device management interfaces to specific authorized IP addresses only
- Disable or block network access to the device if it is not required for operational purposes until patching is possible
- Monitor all network traffic to and from affected devices for suspicious authentication activity
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
