ESB-2018.2551 - [Appliance] Schneider Electric Modicon M221: Multiple vulnerabilities 2018-08-29

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             AUSCERT External Security Bulletin Redistribution

                               ESB-2018.2551
          Advisory (ICSA-18-240-01) and Advisory (ICSA-18-240-02)
                              29 August 2018

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

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

Product:           Schneider Electric Modicon M221
Publisher:         ICS-CERT
Operating System:  Network Appliance
Impact/Access:     Access Privileged Data -- Remote/Unauthenticated
                   Denial of Service      -- Remote/Unauthenticated
Resolution:        Patch/Upgrade
CVE Names:         CVE-2018-7792 CVE-2018-7791 CVE-2018-7790
                   CVE-2018-7789  

Original Bulletin: 
   https://ics-cert.us-cert.gov/advisories/ICSA-18-240-01
   https://ics-cert.us-cert.gov/advisories/ICSA-18-240-02

Comment: This bulletin contains two (2) ICS-CERT security advisories.

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Advisory (ICSA-18-240-01)

Schneider Electric Modicon M221

Original release date: August 28, 2018

Legal Notice

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/.

1. EXECUTIVE SUMMARY

  o CVSS v3 7.7
  o ATTENTION: Exploitable remotely
  o Vendor: Schneider Electric
  o Equipment: Modicon M221
  o Vulnerabilities: Information Management Errors, Permissions, Privileges,
    and Access Controls

2. RISK EVALUATION

Successful exploitation of these vulnerabilities may allow unauthorized users
to replay authentication sequences, overwrite passwords, or decode passwords.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

Schneider Electric reports the vulnerabilities affect the following Modicon
M221 products:

  o Modicon M221, all references, all versions prior to firmware v1.6.2.0

3.2 VULNERABILITY OVERVIEW

3.2.1    INFORMATION MANAGEMENT ERRORS CWE-199

This vulnerability allows unauthorized users to replay authentication
sequences.
If an attacker exploits this vulnerability and connects to a Modicon M221, the
attacker may upload the original program from the PLC.

CVE-2018-7790 has been assigned to this vulnerability. A CVSS v3 base score of
7.1 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:N/UI:R/S:U/C:H
/I:H/A:L).

3.2.2    PERMISSIONS, PRIVILEGES, AND ACCESS CONTROLS CWE-264

This vulnerability allows unauthorized users to overwrite the original
password.
If an attacker exploits this vulnerability and overwrites the password, the
attacker may upload the original program from the PLC.

CVE-2018-7791 has been assigned to this vulnerability. A CVSS v3 base score of
7.7 has been assigned; the CVSS vector string is
(AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L).

3.2.3    PERMISSIONS, PRIVILEGES, AND ACCESS CONTROLS CWE-264

This vulnerability allows unauthorized users to decode the password using a
rainbow table.

CVE-2018-7792 has been assigned to this vulnerability. A CVSS v3 base score of
7.7 has been assigned; the CVSS vector string is
(AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L).

3.3 BACKGROUND

  o CRITICAL INFRASTRUCTURE SECTORS: Commercial Facilities
  o COUNTRIES/AREAS DEPLOYED: Worldwide
  o COMPANY HEADQUARTERS LOCATION: France

3.4 RESEARCHER

Irfan Ahmed, Hyunguk Yoo, Sushma Kalle, and Nehal Ameen of the University of
New Orleans reported these vulnerabilities to NCCIC.

4. MITIGATIONS

A fix for these vulnerabilities is implemented in Modicon M221 Firmware
v1.6.2.0, delivered within SoMachine Basic v1.6 SP2, which is available for
download below, or by using Schneider Electric Software Update tool:

https://www.schneider-electric.com/en/download/document/SoMachineBasicV1.6SP2/

As a temporary mitigation, Modicon M221 users should take the following
measures:

  o Set up a firewall blocking all remote/external access to Port 502.
  o Within the Modicon M221 application, users must disable all unused
    protocols, especially programming protocol, as described in section
    "Configuring Ethernet Network" of SoMachine Basic online help. This will
    prevent remote programming of the M221 PLC.

Schneider Electric's security notice SEVD-2018-235-01 is available at the
following location:

https://www.schneider-electric.com/en/download/document/SEVD-2018-235-01/

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

  o Minimize network exposure for all control system devices and/or systems,
    and ensure that they are not accessible from the Internet.
  o Locate control system networks and remote devices behind firewalls, and
    isolate them from the business network.
  o 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.

NCCIC reminds organizations to perform proper impact analysis and risk
assessment prior to deploying defensive measures.

NCCIC 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
on the ICS-CERT website 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 NCCIC for tracking
and correlation against other incidents.

No known public exploits specifically target these vulnerabilities. High skill
level is needed to exploit.


Contact Information

For any questions related to this report, please contact the NCCIC at:

Email: NCCICCUSTOMERSERVICE@hq.dhs.gov
Toll Free: 1-888-282-0870

For industrial control systems cybersecurity information:
http://ics-cert.us-cert.gov
or incident reporting:  https://ics-cert.us-cert.gov/Report-Incident

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

- -------------------------------------------------------------------------------

Advisory (ICSA-18-240-02)

Schneider Electric Modicon M221

Original release date: August 28, 2018

Legal Notice

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/.

1. EXECUTIVE SUMMARY

  o CVSS v3 4.8
  o ATTENTION: Exploitable remotely
  o Vendor: Schneider Electric
  o Equipment: Modicon M221
  o Vulnerability: Improper Check for Unusual or Exceptional Conditions

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow an unauthorized user
to remotely reboot the device.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following versions of Modicon M221, a programmable logic controller (PLC),
are affected:

  o Modicon M221 all references and versions prior to firmware v1.6.2.0

3.2 VULNERABILITY OVERVIEW

3.2.1    IMPROPER CHECK FOR UNUSUAL OR EXCEPTIONAL CONDITIONS CWE-754

The vulnerability may allow unauthorized users to remotely reboot Modicon M221
using crafted programing protocol frames.

CVE-2018-7789 has been assigned to this vulnerability. A CVSS v3 base score of
4.8 has been calculated; the CVSS vector string is
(AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L).

3.3 BACKGROUND

  o CRITICAL INFRASTRUCTURE SECTORS: Commercial Facilities
  o COUNTRIES/AREAS DEPLOYED: Worldwide
  o COMPANY HEADQUARTERS LOCATION: France

3.4 RESEARCHER

Schneider Electric, working with Yehonatan Kfir of Radiflow, reported the
vulnerability to NCCIC.

4. MITIGATIONS

Schneider Electric reports that a fix for this vulnerability is implemented in
Modicon M221 Firmware v1.6.2.0, delivered within SoMachine Basic v1.6 SP2, or
by using the Schneider Electric Software Update tool.

The download for SoMachine Basic is available at:

https://www.schneider-electric.com/en/download/document/SoMachineBasicV1.6SP2/

For more information, see the Schneider Electric security notification at:

https://www.schneider-electric.com/en/download/document/SEVD-2018-233-01/

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

  o Minimize network exposure for all control system devices and/or systems,
    and ensure that they are not accessible from the Internet.
  o Locate control system networks and remote devices behind firewalls, and
    isolate them from the business network.
  o 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.

NCCIC reminds organizations to perform proper impact analysis and risk
assessment prior to deploying defensive measures.

NCCIC 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
on the ICS-CERT website 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 NCCIC for tracking
and correlation against other incidents.

No known public exploits specifically target this vulnerability. High skill
level is needed to exploit.


Contact Information

For any questions related to this report, please contact the NCCIC at:

Email: NCCICCUSTOMERSERVICE@hq.dhs.gov
Toll Free: 1-888-282-0870

For industrial control systems cybersecurity information:
http://ics-cert.us-cert.gov
or incident reporting:  https://ics-cert.us-cert.gov/Report-Incident

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

- --------------------------END INCLUDED TEXT--------------------

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