As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens’ ProductCERT Security Advisories (CERT Services | Services | Siemens Global). 

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1. EXECUTIVE SUMMARY

CVSS v4 5.1
ATTENTION: Low attack complexity
Vendor: Siemens
Equipment: SENTRON 7KM PAC3120, SENTRON 7KM PAC3220
Vulnerability: Improper Access Control

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow attacker to read out the data from the internal flash of affected device.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following versions of Siemens SENTRON 7KM PAC3120 and PAC3220, power measuring devices, are affected:

SENTRON 7KM PAC3120 AC/DC (7KM3120-0BA01-1DA0): Versions V3.2.3 and after but before V3.3.0 only when manufactured between LQN231003… and LQN231215… (with LQNYYMMDD…)
SENTRON 7KM PAC3120 DC (7KM3120-1BA01-1EA0): Versions V3.2.3 and after but before V3.3.0 only when manufactured between LQN231003… and
LQN231215… (with LQNYYMMDD…)
SENTRON 7KM PAC3220 AC/DC (7KM3220-0BA01-1DA0): Versions V3.2.3 and after but before V3.3.0 only when manufactured between LQN231003… and LQN231215… (with LQNYYMMDD…)
SENTRON 7KM PAC3220 DC (7KM3220-1BA01-1EA0): Versions V3.2.3 and after but before V3.3.0 only when manufactured between LQN231003… and
LQN231215… (with LQNYYMMDD…)

3.2 Vulnerability Overview

3.2.1 IMPROPER ACCESS CONTROL CWE-284

The read out protection of the internal flash of affected devices was not properly set at the end of the
manufacturing process. An attacker with physical access to the device could read out the data.

CVE-2024-21483 has been assigned to this vulnerability. A CVSS v3.1 base score of 4.6 has been calculated; the CVSS vector string is (AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).

A CVSS v4 score has been calculated for CVE-2024-21483. A base score of 5.1 has been calculated; the CVSS vector string is (CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N).

3.3 BACKGROUND

CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing
COUNTRIES/AREAS DEPLOYED: Worldwide
COMPANY HEADQUARTERS LOCATION: Germany

3.4 RESEARCHER

Siemens reported this vulnerability to CISA.

4. MITIGATIONS

Siemens has identified the following specific workarounds and mitigations users can apply to reduce risk:

SENTRON 7KM PAC3120 AC/DC (7KM3120-0BA01-1DA0), SENTRON 7KM PAC3120 DC (7KM3120-1BA01-1EA0), SENTRON 7KM PAC3220 AC/DC (7KM3220-0BA01-1DA0), SENTRON 7KM PAC3220 DC (7KM3220-1BA01-1EA0): Restrict physical access to the device to trusted personnel.
SENTRON 7KM PAC3120 AC/DC (7KM3120-0BA01-1DA0), SENTRON 7KM PAC3120 DC (7KM3120-1BA01-1EA0), SENTRON 7KM PAC3220 AC/DC (7KM3220-0BA01-1DA0), SENTRON 7KM PAC3220 DC (7KM3220-1BA01-1EA0): Update to V3.3.0 or later version.

As a general security measure, Siemens recommends protecting network access to devices with appropriate mechanisms. To operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens’ operational guidelines for industrial security and following recommendations in the product manuals.

Additional information on industrial security by Siemens can be found on the Siemens industrial security webpage.

For more information see the associated Siemens security advisory SSA-792319 in HTML and CSAF.

CISA recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities, such as:

Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet.
Locate control system networks and remote devices behind firewalls and isolating them from business networks.
When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as the connected devices.

CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets.

Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B–Targeted Cyber Intrusion Detection and Mitigation Strategies.

Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.

No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time. This vulnerability is not exploitable remotely.

5. UPDATE HISTORY

March 14, 2024: Initial Publication