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PatchSiren cyber security CVE debrief

CVE-2024-41798 Siemens CVE debrief

CVE-2024-41798 is a critical vulnerability in Siemens SENTRON 7KM PAC3200 power monitoring devices, published on October 8, 2024. The devices use only a 4-digit PIN to protect administrative access via the Modbus TCP interface, which is trivially bypassable through brute-force attacks or by sniffing the unencrypted Modbus traffic. The CVSS 3.1 score of 9.8 reflects network attackability with low complexity, no required privileges or user interaction, and high impact across confidentiality, integrity, and availability. Siemens has stated that no fix is planned and advises treating the PIN as protection against inadvertent operational errors rather than malicious access attempts.

Vendor
Siemens
Product
SENTRON 7KM PAC3200
CVSS
CRITICAL 9.8
CISA KEV
Not listed in stored evidence
Original CVE published
2024-10-08
Original CVE updated
2024-10-08
Advisory published
2024-10-08
Advisory updated
2024-10-08

Who should care

Organizations operating Siemens SENTRON 7KM PAC3200 devices in industrial, commercial, or utility power monitoring environments; OT security teams responsible for Modbus TCP network segmentation; asset owners in critical infrastructure sectors where power monitoring data integrity is essential

Technical summary

The SENTRON 7KM PAC3200 power monitoring device exposes a Modbus TCP interface protected solely by a 4-digit numeric PIN. This provides only 10,000 possible combinations, making online brute-force attacks practical within seconds to minutes. Additionally, Modbus TCP protocol lacks native encryption, allowing passive network attackers to capture PINs and administrative commands in cleartext. Successful authentication grants administrative control over device configuration and measurement data. Siemens has classified this as a design limitation with no planned remediation, directing users to treat the PIN as accidental operation protection rather than a security control.

Defensive priority

critical

Recommended defensive actions

  • Segment Modbus TCP traffic to isolated network zones with strict access controls; do not expose Modbus TCP interfaces to untrusted or internet-facing networks
  • Implement network-level encryption (such as VPN or TLS tunneling) for all Modbus TCP communications to prevent credential sniffing
  • Deploy continuous monitoring and alerting for anomalous Modbus TCP connection attempts to affected devices
  • Treat the 4-digit PIN as operational safety protection only; implement additional authentication layers at network boundaries for administrative access
  • Review and apply CISA ICS recommended practices for defense-in-depth strategies in industrial control environments
  • Contact Siemens support for additional hardening guidance per the FAQ article referenced in the security advisory

Evidence notes

Vulnerability description and remediation guidance sourced from CISA ICS Advisory ICSA-24-284-04 and Siemens Security Advisory SSA-850560. CVSS vector confirms network attack vector with no authentication required.

Official resources

2024-10-08