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Siemens TIM 4R-IE Devices

Act Now9.8ICS-CERT ICSA-21-103-11Apr 13, 2021
Attack VectorNetwork
Auth RequiredNone
ComplexityLow
User InteractionNone needed
Summary

TIM 4R-IE devices contain multiple vulnerabilities in the integrated NTP (Network Time Protocol) component. The vulnerabilities stem from improper input validation (CWE-20), missing authentication mechanisms (CWE-287, CWE-294), and logic errors (CWE-681, CWE-290, CWE-362). These flaws allow remote attackers without credentials to exploit the NTP service. The affected products are all versions of TIM 4R-IE, SIPLUS NET TIM 4R-IE, and their DNP3 variants. No vendor patches are currently available for any affected product version.

What this means
What could happen
An attacker with network access to TIM 4R-IE devices could exploit NTP vulnerabilities to execute arbitrary code, modify network time services, or disrupt communications relied upon by critical control systems that depend on time synchronization for coordinated operations.
Who's at risk
Water treatment and distribution operators, electric utilities, and other critical infrastructure using Siemens TIM 4R-IE remote terminal units for real-time data acquisition and communications. These are often used for remote monitoring and control of pump stations, water quality sensors, SCADA remote stations, and distributed substations.
How it could be exploited
An attacker on the network sends a crafted NTP packet to the device's NTP port. The device fails to validate the input properly (CWE-20) and lacks proper authentication checks (CWE-287, CWE-294), allowing the attacker to execute code with the device's privileges. This could be triggered remotely without credentials or user interaction.
Prerequisites
  • Network access to TIM 4R-IE device NTP port (port 123 UDP)
remotely exploitableno authentication requiredlow complexityhigh EPSS score (79.6%)no patch availableaffects critical infrastructure communications
Exploitability
High exploit probability (EPSS 79.6%)
Affected products (4)
4 EOL
ProductAffected VersionsFix Status
SIPLUS NET TIM 4R-IEAll versionsNo fix (EOL)
SIPLUS NET TIM 4R-IE DNP3All versionsNo fix (EOL)
TIM 4R-IE (6NH7800-4BA00)All versionsNo fix (EOL)
TIM 4R-IE DNP3All versionsNo fix (EOL)
Remediation & Mitigation
0/4
Do now
0/2
HARDENINGRestrict network access to TIM 4R-IE devices using firewall rules and network segmentation—block unauthorized traffic to NTP port (UDP 123) from non-trusted networks
WORKAROUNDDisable NTP service on TIM 4R-IE devices if time synchronization is not required or can be managed through other secure means
Schedule — requires maintenance window
0/1

Patching may require device reboot — plan for process interruption

HARDENINGImplement network segmentation to isolate TIM 4R-IE devices in a protected control network separate from enterprise IT networks
Mitigations - no patch available
0/1
The following products have reached End of Life with no planned fix: SIPLUS NET TIM 4R-IE, SIPLUS NET TIM 4R-IE DNP3, TIM 4R-IE (6NH7800-4BA00), TIM 4R-IE DNP3. Apply the following compensating controls:
HARDENINGFollow Siemens operational guidelines for Industrial Security to harden the overall environment and device configuration
View full CISA ICS-CERT advisory
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Siemens TIM 4R-IE Devices | CVSS 9.8 - OTPulse