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AUSCERT External Security Bulletin Redistribution
Advisory (icsa-19-192-02) Siemens SIMATIC WinCC and PCS7
11 October 2019
AusCERT Security Bulletin Summary
Product: Siemens SIMATIC WinCC
Siemens SIMATIC PCS7
Operating System: Windows
Impact/Access: Execute Arbitrary Code/Commands -- Existing Account
Create Arbitrary Files -- Existing Account
Denial of Service -- Existing Account
CVE Names: CVE-2019-10935
Revision History: October 11 2019: Update to Update C
July 12 2019: Initial Release
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ICS Advisory (ICSA-19-192-02)
Siemens SIMATIC WinCC and PCS7 (Update C)
Original release date: October 10, 2019
All information products included in http://ics-cert.us-cert.gov are
provided"as is" for informational purposes only. The Department of Homeland
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For more information about TLP, see http://www.us-cert.gov/tlp/ .
1. EXECUTIVE SUMMARY
o CVSS v3 7.2
o ATTENTION: Exploitable remotely/low skill level to exploit
o Vendor: Siemens
o Equipment: SIMATIC WinCC and SIMATIC PCS7
o Vulnerability: Unrestricted Upload of File with Dangerous Type
2. UPDATE INFORMATION
This updated advisory is a follow-up to the advisory update titled
ICSA-19-192-02 Siemens SIMATIC WinCC and PCS7 (Update B) that was published
September 10, 2019, on the ICS webpage of us-cert.gov.
3. RISK EVALUATION
Successful exploitation of this vulnerability could cause a denial-of-service
condition on the affected service or device.
4. TECHNICAL DETAILS
4.1 AFFECTED PRODUCTS
The following Siemens industrial products are affected:
o SIMATIC PCS 7 v8.0: all versions
o SIMATIC PCS 7 v8.1: all versions prior to v8.1 with WinCC v7.3 Upd 19
o SIMATIC PCS 7 v8.2: all versions prior to v8.2 SP1 with WinCC v7.4 SP1 Upd
o SIMATIC PCS 7 v9.0: all versions prior to v9.0 SP2 with WinCC v7.4 SP1 Upd
o SIMATIC WinCC Professional (TIA Portal v13): all versions
- --------- Begin Update C Part 1 of 2 --------
o SIMATIC WinCC Professional (TIA Portal v14): all versions prior to v14 SP1
o SIMATIC WinCC Professional (TIA Portal v15): all versions prior to v15.1
o SIMATIC WinCC Runtime Professional v14: all versions prior to v14.1 Upd 8
o SIMATIC WinCC Runtime Professional v15: all versions prior to v15.1 Upd 3
- --------- End Update C Part 1 of 2 --------
o SIMATIC WinCC v7.2 and earlier: all versions
o SIMATIC WinCC v7.3: all versions prior to v7.3 Upd 19
o SIMATIC WinCC v7.4: all versions prior to v7.4 SP1 Upd 11
o SIMATIC WinCC v7.5: all versions prior to v7.5 Upd 3
4.2 VULNERABILITY OVERVIEW
4.2.1 UNRESTRICTED UPLOAD OF FILE WITH DANGEROUS TYPE CWE-434
The SIMATIC WinCC DataMonitor web application of the affected products allows
an authenticated user with network access to the WinCC DataMonitor application
to upload arbitrary ASPX code.
Successful exploitation requires no user interaction and may impact the
confidentiality, integrity, and availability of the affected device. The
vulnerability is relevant only in situations where an attacker has access via
the web interface but not to the directory structure.
CVE-2019-10935 has been assigned to this vulnerability. A CVSS v3 base score of
7.2 has been calculated; the CVSS vector string is ( AV:N/AC:L/PR:H/UI:N/S:U/
o CRITICAL INFRASTRUCTURE SECTORS: Chemical, Critical Manufacturing, Energy,
Food and Agriculture, Water and Wastewater Systems
o COUNTRIES/AREAS DEPLOYED: Worldwide
o COMPANY HEADQUARTERS LOCATION: Germany
Xuchen Zhu from ZheJiang Guoli Security Technology and CNCERT/CC reported this
vulnerability to Siemens.
Siemens currently has updates for the following products:
o SIMATIC PCS 7 v8.1: Update WinCC to v7.3 Upd 19
o SIMATIC PCS 7 v8.2: Update WinCC to v7.4 SP1 Upd 11
o SIMATIC PCS 7 v9.0: Update WinCC to v7.4 SP1 Upd 11
o SIMATIC WinCC v7.3: Update WinCC to v7.3 Upd 19
o SIMATIC WinCC v7.4: Update WinCC to v7.4 SP1 Upd 11
o SIMATIC WinCC v7.5: Update WinCC to v7.5 Upd 3
- --------- Begin Update C Part 2 of 2 --------
o SIMATIC WinCC Runtime Professional (TIA Portal v14): Update v14 SP1 Upd 9
o SIMATIC WinCC Runtime Professional (TIA Portal v15): Update v15.1 Upd 3
o SIMATIC WinCC Runtime Professional v14: Update v14.1 Upd 8
o SIMATIC WinCC Runtime Professional v15: Update v15.1 Upd 3
- --------- End Update C Part 2 of 2 ---------
For the balance of the listed products, Siemens is preparing further updates
and recommends users apply the following specific workarounds and mitigations
to reduce risk until patches are available:
o Apply defense in depth.
Siemens recommends users configure their environment according to Siemens'
operational guidelines for industrial security ( Download ) and follow the
recommendations in the product manuals.
Additional information on Industrial Security by Siemens can be found at:
For more information on the vulnerability and more detailed mitigation
instructions, please see Siemens security advisory SSA-121293 at the following
CISA 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.
CISA reminds organizations to perform proper impact analysis and risk
assessment prior to deploying defensive measures.
CISA also provides a section for control systems security recommended practices
on the ICS webpage on us-cert.gov . Several recommended practices are available
for reading and download, including I mproving Industrial Control Systems
Cybersecurity with Defense-in-Depth Strategies .
Additional mitigation guidance and recommended practices are publicly available
on the ICS webpage on us-cert.gov in the Technical Information Paper,
ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation
Organizations observing any suspected malicious activity should follow their
established internal procedures and report their findings to CISA for tracking
and correlation against other incidents.
No known public exploits specifically target this vulnerability.
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