Siemens Tecnomatix Plant Simulation

1. EXECUTIVE SUMMARY

• CVSS v3 7.8 ***ATTENTION: **Low attack complexity
• **Vendor:**Siemens
• Equipment: Tecnomatix Plant Simulation
• **Vulnerabilities:**Stack-based Buffer Overflow, Improper Restriction of Operations within the Bounds of a Memory Buffer

2. RISK EVALUATION

Successful exploitation of these vulnerabilities could lead to arbitrary code execution.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following versions of Tecnomatix Plant Simulation are affected:

• Tecnomatix Plant Simulation: All Versions prior to 16.0.5

3.2 VULNERABILITY OVERVIEW

3.2.1 STACK-BASED BUFFER OVERFLOW CWE-121

The PlantSimCore.dll library lacks proper validation of user-supplied data when parsing SPP files. This could result in a stack-based buffer overflow. An attacker could leverage this vulnerability to execute code in the context of the current process.

CVE-2021-27396 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

3.2.2 IMPROPER RESTRICTION OF OPERATIONS WITHIN THE BOUNDS OF A MEMORY BUFFER CWE-119

The PlantSimCore.dll library lacks proper validation of user-supplied data when parsing SPP files. This could result in a memory-corruption condition. An attacker could leverage this vulnerability to execute code in the context of the current process.

CVE-2021-27397 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

3.2.3 STACK-BASED BUFFER OVERFLOW CWE-121

The PlantSimCore.dll library lacks proper validation of user-supplied data when parsing SPP files. This could result in a stack-based buffer overflow. An attacker could leverage this vulnerability to execute code in the context of the current process.

CVE-2021-27398 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

3.3 BACKGROUND

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

3.4 RESEARCHER

Francis Provencher {PRL} working with Trend Micro’s Zero Day Initiative reported these vulnerabilities to CISA.

4. MITIGATIONS

Siemens recommends the following:

• Update to v16.0.5 or later
• Do not open untrusted SPP files from unknown sources.

As a general security measure, Siemens strongly 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](<https://cert-portal.siemens.com/operational-guidelines-industrial-security.pdf >), and to follow the recommendations in the product manuals.

Additional information on industrial security by Siemens can be found at: <https://www.siemens.com/industrialsecurity&gt;

For more information see SSA-983548

CISA also recommends users take the following measures to protect themselves from social engineering attacks:

• Do not click web links or open unsolicited attachments in email messages.
• Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams.
• Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.

CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:

• Minimize network exposure for all control system devices and/or systems, and ensure that they are not accessible from the Internet.
• Locate control system networks and remote devices behind firewalls, and isolate them from the business network.
• When remote access is required, use 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 its 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 us-cert.cisa.gov. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

Additional mitigation guidance and recommended practices are publicly available on the ICS webpage on us-cert.cisa.gov in the Technical Information Paper, ICS-TIP-12-146-01B–Targeted Cyber Intrusion Detection and Mitigation Strategies.

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

No known public exploits specifically target these vulnerabilities. These vulnerabilities are not exploitable remotely.