Siemens SICAM PAS Vulnerabilities (Update A)

OVERVIEW

This updated advisory is a follow-up to the original advisory titled ICSA-16-336-01 Siemens SICAM PAS Vulnerabilities that was published December 1, 2016, on the NCCIC/ICS-CERT web site.

Siemens has released an advisory to inform its users on how to mitigate vulnerabilities that affect SICAM PAS. Ilya Karpov and Dmitry Sklyarov of Positive Technologies and Sergey Temnikov and Vladimir Dashchenko of Kaspersky Lab coordinated these vulnerabilities directly with Siemens. Siemens has produced an update to mitigate some of these vulnerabilities.

Some of these vulnerabilities could be exploited remotely.

AFFECTED PRODUCTS

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The following SICAM PAS versions are affected:

• SICAM PAS: All versions prior to 8.09.

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IMPACT

Successful exploitation of these vulnerabilities may allow an attacker to cause a denial-of-service condition or remotely exploit arbitrary code.

Impact to individual organizations depends on many factors that are unique to each organization. NCCIC/ICS-CERT recommends that organizations evaluate the impact of these vulnerabilities based on their operational environment, architecture, and product implementation.

BACKGROUND

Siemens is a multinational company headquartered in Munich, Germany.

The affected product, SICAM PAS, is energy automation software for operating electrical substations. According to Siemens, SICAM PAS is deployed across the Energy sector. Siemens estimates that this product is used worldwide.

VULNERABILITY CHARACTERIZATION

VULNERABILITY OVERVIEW

A factory account with hard-coded passwords is present in the SICAM PAS installations. Attackers might gain privileged access to the database over Port 2638/TCP.

SICAM PAS Versions 8.00 and higher are not affected by this vulnerability.

CVE-2016-8567NVD, https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-8567, NIST uses this advisory to create the CVE web site report. This web site will be active sometime after publication of this advisory. has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).CVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, web site last accessed December 01, 2016.

An authenticated local attacker with certain privileges could possibly reconstruct the passwords of users for accessing the database.

SICAM PAS Versions 8.00 and higher are not affected by this vulnerability.

CVE-2016-8566NVD, https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-8566, NIST uses this advisory to create the CVE web site report. This web site will be active sometime after publication of this advisory. 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:L/UI:N/S:U/C:H/I:H/A:H).CVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, web site last accessed December 01, 2016.

A remote attacker could use specially crafted packets sent to Port 19235/TCP to upload, download, or delete files in certain parts of the file system.

CVE-2016-9156NVD, https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-9156, NIST uses this advisory to create the CVE web site report. This web site will be active sometime after publication of this advisory. has been assigned to this vulnerability. A CVSS v3 base score of 7.3 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L).CVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L, web site last accessed December 01, 2016.

Specially crafted packets sent to port 19234/TCP could cause a denial of service condition and potentially lead to unauthenticated remote code execution.

CVE-2016-9157NVD, https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-9157, NIST uses this advisory to create the CVE web site report. This web site will be active sometime after publication of this advisory. has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).CVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, web site last accessed December 01, 2016.

VULNERABILITY DETAILS

EXPLOITABILITY

Some of these vulnerabilities could be exploited remotely.

EXISTENCE OF EXPLOIT

No known public exploits specifically target these vulnerabilities.

DIFFICULTY

An attacker with low skill would be able to exploit these vulnerabilities.

MITIGATION

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SICAM PAS Versions 8.09 and higher fix all four vulnerabilities. Siemens recommends that users upgrade to the latest version. In order to receive the SICAM PAS V8.09 update, please contact the Siemens Energy Customer Support Center at support.energy@siemens.com.

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Siemens strongly recommends users protect network access with appropriate mechanisms (e.g., firewalls, segmentation, VPN). Siemens also advises that users configure the operational environment according to Siemens’ Operational Guidelines for Industrial Security:

https://www.siemens.com/cert/operational-guidelines-industrial-security

For more information on this vulnerability and more detailed mitigation instructions, please see Siemens Security Advisory SSA-946325 at the following location:

http://www.siemens.com/cert/advisories

ICS-CERT recommends that users take defensive measures to minimize the risk of exploitation of these vulnerabilities. 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 that VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize that VPN is only as secure as the connected devices.

ICS-CERT reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

ICS-CERT also provides a section for control systems security recommended practices on the ICS-CERT web page. 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 in the ICS‑CERT Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies, that is available for download from the ICS-CERT web site.

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