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             AUSCERT External Security Bulletin Redistribution

                              ESB-2018.0208.2
         Multiple vulnerabilities have been identified in Siemens
                           SIMATIC WinCC Add-On
                             28 February 2018

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

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

Product:           Siemens SIMATIC WinCC
Publisher:         ICS-CERT
Operating System:  Windows
Impact/Access:     Execute Arbitrary Code/Commands -- Remote/Unauthenticated
                   Denial of Service               -- Remote/Unauthenticated
                   Access Confidential Data        -- Remote/Unauthenticated
                   Reduced Security                -- Remote/Unauthenticated
Resolution:        Patch/Upgrade
CVE Names:         CVE-2017-12822 CVE-2017-12821 CVE-2017-12820
                   CVE-2017-12819 CVE-2017-12818 CVE-2017-11498
                   CVE-2017-11497 CVE-2017-11496 

Original Bulletin: 
   https://ics-cert.us-cert.gov/advisories/ICSA-18-018-01A

Revision History:  February 28 2018: Bulletin updated with additional CVEs
                   January  19 2018: Initial Release

- --------------------------BEGIN INCLUDED TEXT--------------------

Advisory (ICSA-18-018-01A)
Siemens SIMATIC WinCC Add-On (Update A)
Original release date: January 18, 2018 | Last revised: February 27, 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/.

CVSS v3 9.8

ATTENTION: Remotely exploitable/low skill level to exploit.

Vendor: Siemens

Equipment: SIMATIC WinCC Add-On

Vulnerabilities: Stack-based Buffer Overflow, Improper Input Validation,
Improper Restriction of Operations within the Bounds of a Memory Buffer,
Security Features, Improper Access Control.

UPDATE INFORMATION

This updated advisory is a follow-up to the original advisory titled
ICSA-18-018-01 Siemens SIMATIC WinCC Add-On that was published January 18,
2018, on the NCCIC/ICS-CERT website.

AFFECTED PRODUCTS

Siemens reports that the vulnerabilities affect the following versions of
SIMATIC WinCC Add-On:

SIMATIC WinCC Add-On Historian CONNECT ALARM all versions prior to and including v5.x,
SIMATIC WinCC Add-On PI CONNECT ALARM all versions prior to and including v2.x,
SIMATIC WinCC Add-On PI CONNECT AUDIT TRAIL all versions prior to and including v1.x,
SIMATIC WinCC Add-On PM-AGENT all versions prior to and including v5.x,
SIMATIC WinCC Add-On PM-ANALYZE all versions prior to and including v7.x,
SIMATIC WinCC Add-On PM-CONTROL all versions prior to and including v10.x,
SIMATIC WinCC Add-On PM-MAINT all versions prior to and including v9.x,
SIMATIC WinCC Add-On PM-OPEN EXPORT all versions prior to and including v7.x,
SIMATIC WinCC Add-On PM-OPEN HOST-S all versions prior to and including v7.x,
SIMATIC WinCC Add-On PM-OPEN IMPORT all versions prior to and including v6.x,
SIMATIC WinCC Add-On PM-OPEN PI all versions prior to and including v7.x,
SIMATIC WinCC Add-On PM-OPEN PV02 all versions prior to and including v1.x,
SIMATIC WinCC Add-On PM-OPEN TCP/IP all versions prior to and including v8.x,
SIMATIC WinCC Add-On PM-QUALITY all versions prior to and including v9.x,
SIMATIC WinCC Add-On SICEMENT IT MIS all versions prior to and including v7.x, and
SIMATIC WinCC Add-On SIPAPER IT MIS all versions prior to and including v7.x

IMPACT

Successful exploitation of these vulnerabilities could allow remote code
execution or a denial of service condition.

MITIGATION

Gemalto has released an updated installer and Siemens strongly encourages
users upgrade to the new installer as soon as possible. The new installer
is available at:

https://supportportal.gemalto.com/csm/?id=kb_article&sys_id=a459d328dba207c8fe0aff3dbf9619ce
(link is external)

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
(link is external)

For more information on these vulnerabilities and more detailed mitigation
instructions, please see Siemens Security Advisory SSA-127490 at the
following location:

http://www.siemens.com/cert/advisories (link is external)

NCCIC recommends 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.

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 in the NCCIC Technical Information Paper,
ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation
Strategies, that is available for download from the ICS-CERT website.

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.

VULNERABILITY OVERVIEW

STACK-BASED BUFFER OVERFLOW CWE-121

Malformed ASN1 streams in V2C and similar input files can be used to
generate stack-based buffer overflows. The vulnerability could allow
arbitrary code execution.

CVE-2017-11496 has been assigned to this vulnerability. A CVSS
v3 base score of 9.8 has been assigned; the CVSS vector string is
(AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

STACK-BASED BUFFER OVERFLOW CWE-121

Language packs containing malformed filenames could lead to a stack-based
buffer overflow. The vulnerability could allow arbitrary code execution.

CVE-2017-11497 has been assigned to this vulnerability. A CVSS
v3 base score of 9.8 has been assigned; the CVSS vector string is
(AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

IMPROPER INPUT VALIDATION CWE-20

Language pack (ZIP file) with invalid HTML files could lead to NULL
pointer access. The vulnerability could cause denial of service of the
remote process.

CVE-2017-11498 has been assigned to this vulnerability. A CVSS
v3 base score of 7.5 has been assigned; the CVSS vector string is
(AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

- --------- Begin Update A Part 1 of 1 --------

IMPROPER RESTRICTION OF OPERATIONS WITHIN THE BOUNDS OF A MEMORY BUFFER
CWE-119

A stack overflow flaw in the custom XML parser could allow remote denial
of service.

CVE-2017-12818 has been assigned to this vulnerability. A CVSS
v3 base score of 7.5 has been assigned; the CVSS vector string is
(AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

SECURITY FEATURES CWE-254

Remote manipulation of the language pack updater could allow NTLM relay
attacks.

CVE-2017-12819 has been assigned to this vulnerability. A CVSS
v3 base score of 9.8 has been assigned; the CVSS vector string is
(AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

IMPROPER RESTRICTION OF OPERATIONS WITHIN THE BOUNDS OF A MEMORY BUFFER
CWE-119

Arbitrary memory read from controlled memory pointer could allow remote
denial of service.

CVE-2017-12820 has been assigned to this vulnerability. A CVSS
v3 base score of 7.5 has been assigned; the CVSS vector string is
(AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

IMPROPER RESTRICTION OF OPERATIONS WITHIN THE BOUNDS OF A MEMORY BUFFER
CWE-119

A memory corruption flaw could allow remote code execution.

CVE-2017-12821 has been assigned to this vulnerability. A CVSS
v3 base score of 9.8 has been assigned; the CVSS vector string is
(AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

IMPROPER ACCESS CONTROL CWE-284

The administrative interface can be remotely enabled and disabled without
authentication. This could increase the attack surface.

CVE-2017-12822 has been assigned to this vulnerability. A CVSS
v3 base score of 5.3 has been assigned; the CVSS vector string is
(AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N).

- --------- End Update A Part 1 of 1 ----------

RESEARCHER

Sergey Temnikov and Vladimir Dashchenko from Kaspersky Lab reported these
vulnerabilities to Siemens.

BACKGROUND

Critical Infrastructure Sectors: Chemical, Energy, Food and Agriculture,
Water and Wastewater Systems.

Countries/Areas Deployed: Worldwide

Company Headquarters Location: Germany

Contact Information

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

Email: NCCICCUSTOMERSERVICE@hq.dhs.gov (link sends e-mail)
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?

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