OVERVIEW

Siemens has identified authentication vulnerabilities in the SIMATIC WinCC [email protected] Client application. These vulnerabilities were reported directly to Siemens by Kim Schlyter, Seyton Bradford, and Richard Warren from FortConsult (NCC Group). Siemens has produced an update that mitigates these vulnerabilities.

AFFECTED PRODUCTS

The following SIMATIC WinCC [email protected] Client versions are affected:

• SIMATIC WinCC [email protected]: All versions prior to V1.0.2
• SIMATIC WinCC [email protected] Lite for iOS: All versions prior to V1.0.2.

IMPACT

An attacker with local access could use these vulnerabilities to escalate privileges on the application or the servers with which the application is communicating.

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 an international company headquartered in Munich, Germany.

The SIMATIC WinCC [email protected] application, in combination with the SIMATIC WinCC [email protected], allows remote mobile operation and observation of SIMATIC HMI systems. This software is deployed across several sectors including Chemical, Energy, Food and Agriculture, and Water and Wastewater Systems. Siemens estimates that these products are used primarily in the United States and Europe with a small percentage in Asia.

VULNERABILITY CHARACTERIZATION

VULNERABILITY OVERVIEW

The existing storage mechanism for the application specific password could allow attackers to extract the password and gain access to the application if local access is available.

CVE-2014-5231b has been assigned to this vulnerability. A CVSS v2 base score of 4.6 has been assigned; the CVSS vector string is (AV:L/AC:L/Au:N/C:P/I:P/A:P).c

In case an application specific password is set, the user would not be prompted to enter the password if the application was resumed from the background.

CVE-2014-5232e has been assigned to this vulnerability. A CVSS v2 base score of 4.6 has been assigned; the CVSS vector string is (AV:L/AC:L/Au:N/C:P/I:P/A:P).f

The implemented mechanism to process [email protected] credentials could allow attackers to extract the credentials if local access is available.

CVE-2014-5233h has been assigned to this vulnerability. A CVSS v2 base score of 4.6 has been assigned; the CVSS vector string is (AV:L/AC:L/Au:N/C:P/I:P/A:P).i

VULNERABILITY DETAILS

EXPLOITABILITY

An attacker must have local access to the mobile device to exploit these vulnerabilities.

EXISTENCE OF EXPLOIT

No known public exploits specifically target these vulnerabilities.

DIFFICULTY

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

MITIGATION

Siemens has released SIMATIC WinCC [email protected] V1.0.2 for iOS, which fixes these vulnerabilities and recommends upgrading as soon as possible. These updates are available on iTunes at:

https://itunes.apple.com/gb/app/simatic-wincc-sm-rtclient/id871870286

https://itunes.apple.com/de/app/simatic-wincc-sm-rtclient/id874209707

For more information on these vulnerabilities and detailed instructions, please see Siemens Security Advisory SSA-311299 at the following location:

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

ICS-CERT encourages asset owners to take additional defensive measures to protect against this and other cybersecurity risks.

• 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 also provides a section for control systems security recommended practices on the ICS-CERT web page at: http://ics-cert.us-cert.gov/content/recommended-practices. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies. ICS-CERT reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

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 (http://ics-cert.us-cert.gov/).

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.

• a. CWE-522: Insufficiently Protected Credentials, http://cwe.mitre.org/data/definitions/522.html, web site last accessed January 13, 2015.
• b. NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2014-5231, NIST uses this advisory to create the CVE web site report. This web site will be active sometime after publication of this advisory.
• c. CVSS Calculator, http://nvd.nist.gov/cvss.cfm?version=2&vector=AV:L/AC:L/Au:N/C:P/I:P/A:P, web site last accessed January 13, 2015.
• d. CWE-287: Improper Authentication, http://cwe.mitre.org/data/definitions/287.html, web site last accessed January 13, 2015.
• e. NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2014-5232, NIST uses this advisory to create the CVE web site report. This web site will be active sometime after publication of this advisory.
• f. CVSS Calculator, http://nvd.nist.gov/cvss.cfm?version=2&vector=AV:L/AC:L/Au:N/C:P/I:P/A:P, web site last accessed January 13, 20155.
• g. CWE-522: Insufficiently Protected Credentials, http://cwe.mitre.org/data/definitions/522.html, web site last accessed January 13, 2015.
• h. NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2014-5233, NIST uses this advisory to create the CVE web site report. This web site will be active sometime after publication of this advisory.
• i. CVSS Calculator, http://nvd.nist.gov/cvss.cfm?version=2&vector=AV:L/AC:L/Au:N/C:P/I:P/A:P, web site last accessed January 13, 2015.