Siemens SIMATIC eaSie PCS 7 Skill Package

1. EXECUTIVE SUMMARY

• CVSS v3 6.5
• ATTENTION: Exploitable remotely/low attack complexity
• Vendor: Siemens
• Equipment: SIMATIC eaSie PCS 7 Skill Package
• Vulnerability: Path Traversal

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow an authenticated remote attacker to read arbitrary files on the application server.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following versions of SIMATIC eaSie PCS 7 Skill Package, a digital assistant, are affected:

• SIMATIC eaSie PCS 7 Skill Package (6DL5424-0BX00-0AV8): All versions prior to 21.00 SP3

3.2 VULNERABILITY OVERVIEW

3.2.1     IMPROPER LIMITATION OF A PATHNAME TO A RESTRICTED DIRECTORY (‘PATH TRAVERSAL’) CWE-22

When downloading files, the affected systems do not properly neutralize special elements within the pathname. An attacker could then cause the pathname to resolve to a location outside of the restricted directory on the server and read unexpected critical files. The affected file download function is disabled by default.

CVE-2021-42022 has been assigned to this vulnerability. A CVSS v3 base score of 6.5 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A: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 recommends users update to v21.00 SP3 or later version.

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, and following the recommendations in the product manuals. Additional information on industrial security by Siemens can be found at: https://www.siemens.com/industrialsecurity

For more information see Siemens Security Advisory SSA-199605

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. 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 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 this vulnerability.

• Siemens