Siemens SIMATIC CN 4100
Act Now10ICS-CERT ICSA-24-137-06May 14, 2024
Attack VectorNetwork
Auth RequiredNone
ComplexityLow
User InteractionNone needed
Summary
SIMATIC CN 4100 firmware versions below 3.0 contain hard-coded root user credentials that allow unauthenticated remote login, and feature an unrestricted USB port that could be exploited to boot malicious firmware or bypass security controls. The device is typically deployed as a network communication node or gateway in industrial control systems. Siemens has released version 3.0 to address these vulnerabilities.
What this means
What could happen
An attacker with network access to the SIMATIC CN 4100 could exploit hard-coded root credentials to gain full control of the device and potentially modify network or system configurations, or boot malicious firmware via the unrestricted USB port, disrupting communication and control operations.
Who's at risk
Water utilities, municipal electric utilities, and any critical infrastructure operators using Siemens SIMATIC CN 4100 industrial gateways or control nodes should prioritize this update. The CN 4100 is commonly deployed as a network gateway or communication hub in industrial automation systems; compromise could disrupt SCADA visibility and control capabilities across the facility.
How it could be exploited
An attacker on the same network segment as the SIMATIC CN 4100 could enumerate the device, obtain the hard-coded root credentials from public documentation or reverse engineering, and use SSH or similar protocols to log in remotely with full system access. Alternatively, if the attacker has physical access, they could insert a malicious USB device into the unrestricted USB port to boot unauthorized firmware or extract sensitive data.
Prerequisites
- Network access to the SIMATIC CN 4100 management interface (typically SSH, HTTP, or industrial protocols)
- Knowledge of hard-coded root user credentials (publicly available or easily derived)
- For USB exploitation: physical access to the device
Remotely exploitableNo authentication requiredHard-coded credentialsAffects control system gatewaysLow complexityUSB physical access vector
Exploitability
Low exploit probability (EPSS 0.9%)
Affected products (1)
ProductAffected VersionsFix Status
SIMATIC CN 4100<V3.03.0
Remediation & Mitigation
0/4
Do now
0/2WORKAROUNDRestrict network access to the SIMATIC CN 4100 using firewall rules; allow only authorized engineering workstations and management networks to reach the device
HARDENINGDisable or physically protect the USB port if it is not required for normal operations
Schedule — requires maintenance window
0/1Patching may require device reboot — plan for process interruption
HOTFIXUpdate SIMATIC CN 4100 to firmware version 3.0 or later
Long-term hardening
0/1HARDENINGIsolate the SIMATIC CN 4100 and its network segment from the business network using air-gapping or VLAN segmentation
↑↓ Navigate · Esc Close
API:
/api/v1/advisories/18df41fa-ba80-4f1b-9cc1-8f17b567a7eb