Operating System:

[Appliance]

Published:

04 November 2016

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             AUSCERT External Security Bulletin Redistribution

                               ESB-2016.2610
    Schneider Electric Magelis HMI Resource Consumption Vulnerabilities
                              4 November 2016

===========================================================================

        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           Schneider Electric Magelis HMI
Publisher:         ICS-CERT
Operating System:  Network Appliance
Impact/Access:     Denial of Service -- Remote/Unauthenticated
Resolution:        Mitigation
CVE Names:         CVE-2016-8374 CVE-2016-8367 

Original Bulletin: 
   http://ics-cert.us-cert.gov/advisories/ICSA-16-308-02

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Advisory (ICSA-16-308-02)

Schneider Electric Magelis HMI Resource Consumption Vulnerabilities

Original release date: November 03, 2016

All information products included in http://ics-cert.us-cert.gov are provided
"as is" for informational purposes only. The Department of Homeland Security 
(DHS) does not provide any warranties of any kind regarding any information 
contained within. DHS does not endorse any commercial product or service, 
referenced in this product or otherwise. Further dissemination of this product
is governed by the Traffic Light Protocol (TLP) marking in the header. For 
more information about TLP, see http://www.us-cert.gov/tlp/.

OVERVIEW

NCCIC/ICS-CERT is aware of a public report of resource consumption 
vulnerabilities affecting Schneider Electric's Magelis human-machine interface
(HMI) products. The researcher Eran Goldstein, in collaboration with Check 
Point Software Technologies and CRITIFENCE, released vulnerability information
after coordination with the vendor and ICS-CERT. Schneider Electric has 
validated the resource consumption vulnerabilities and is planning to release
new versions to mitigate these vulnerabilities.

These vulnerabilities could be exploited remotely.

Detailed vulnerability information is publicly available that could be used to
develop an exploit that targets these vulnerabilities.

AFFECTED PRODUCTS

Schneider Electric reports that the vulnerabilities affect the following 
versions of Magelis HMI:

Magelis GTO Advanced Optimum Panels, all versions,

Magelis GTU Universal Panel, all versions,

Magelis STO5xx and STU Small panels, all versions,

Magelis XBT GH Advanced Hand-held Panels, all versions,

Magelis XBT GK Advanced Touchscreen Panels with Keyboard, all versions,

Magelis XBT GT Advanced Touchscreen Panels, all versions, and

Magelis XBT GTW Advanced Open Touchscreen Panels (Windows XPe).

IMPACT

Successful exploitation of these vulnerabilities could result in a denial of 
service for the affected devices.

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

BACKGROUND

Schneider Electric's corporate headquarters is located in Paris, France, and 
maintains offices in more than 100 countries worldwide.

The affected products, Magelis, are human-machine interfaces. According to 
Schneider Electric, the Magelis HMIs are deployed across several sectors 
including Critical Manufacturing, and Food and Agriculture. Schneider Electric
estimates that these products are used worldwide.

VULNERABILITY CHARACTERIZATION

VULNERABILITY OVERVIEW

UNCONTROLLED RESOURCE CONSUMPTION [a]

An attacker can open multiple connections to a targeted web server and keep 
connections open preventing new connections from being made, rendering the web
server unavailable during an attack.

CVE-2016-8367 [b] has been assigned to this vulnerability. Schneider 
Electric's CVSS v3 base score of 5.3 has been calculated; the CVSS vector 
string is (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L). [c]

UNCONTROLLED RESOURCE CONSUMPTION [d]

An attacker may be able to disrupt a targeted web server, resulting in a 
denial of service. The disruption requires the affected device to be rebooted
in order to regain operation.

CVE-2016-8374 [e] has been assigned to this vulnerability. Schneider 
Electric's CVSS v3 base score of 7.5 has been calculated; the CVSS vector 
string is (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H). [f]

VULNERABILITY DETAILS

EXPLOITABILITY

These vulnerabilities could be exploited remotely.

EXISTENCE OF EXPLOIT

Detailed vulnerability information is publicly available that could be used to
develop an exploit that targets these vulnerabilities.

DIFFICULTY

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

MITIGATION

Schneider Electric is working to release new versions for the affected 
products that mitigate the identified vulnerabilities, which is planned for 
release by the end of March 2017.

Schneider Electric recommends that users apply the following measures to 
minimize potential exposure:

Minimize network exposure for all control system devices and/or systems, and 
ensure that they are not accessible from the Internet.

Minimize potential attack surface by leaving the Web Gate Server set to its 
default disabled state if it is not needed.

Place control system networks and devices behind firewalls, and isolate them 
from the business network.

Limit traffic on the local network with managed switches.

Where possible, avoid Wi-Fi capabilities; but when Wi-Fi is essential, use 
only secure communications (such as WPA2 encryption).

Do not grant access to unknown computers.

When remote access is essential, use secure methods, such as Virtual Private 
Networks (VPNs); and ensure the remote access solution(s), as well as the 
remote computer(s), are kept up-to-date with the latest security patches.

For further information on vulnerabilities, please visit the Schneider 
Electric cybersecurity web page at:

http://www.schneider-electric.com/en/download/document/SEVD-2016-302-01/ (link
is external)

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.

a. CWE-400: Uncontrolled Resource Consumption ('Resource Exhaustion'), 
https://cwe.mitre.org/data/definitions/400.html, web site last accessed 
November 3, 2016.

b. NVD, https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-8367, 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, 
https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S..., 
web site last accessed November 3, 2016.

d. CWE-400: Uncontrolled Resource Consumption ('Resource Exhaustion'), 
https://cwe.mitre.org/data/definitions/400.html, web site last accessed 
November 3, 2016.

e. NVD, https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-8374, 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, 
https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S..., 
web site last accessed November 3, 2016.

Contact Information

For any questions related to this report, please contact ICS-CERT at:

Email: ics-cert@hq.dhs.gov (link sends e-mail)

Toll Free: 1-877-776-7585

International Callers: (208) 526-0900

For industrial control systems security information and incident reporting: 
http://ics-cert.us-cert.gov

ICS-CERT continuously strives to improve its products and services. You can 
help by choosing one of the links below to provide feedback about this 
product.

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