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AUSCERT External Security Bulletin Redistribution
ESB-2020.3079
Advisory (icsa-20-252-08) Siemens Polarion Subversion Webclient
9 September 2020
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AusCERT Security Bulletin Summary
---------------------------------
Product: Siemens Polarion Subversion Webclient
Publisher: US-CERT
Operating System: Network Appliance
Impact/Access: Cross-site Scripting -- Remote with User Interaction
Cross-site Request Forgery -- Remote with User Interaction
Resolution: Patch/Upgrade
CVE Names: CVE-2020-15789 CVE-2020-15788
Original Bulletin:
https://us-cert.cisa.gov/ics/advisories/icsa-20-252-08
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ICS Advisory (ICSA-20-252-08)
Siemens Polarion Subversion Webclient
Original release date: September 08, 2020
Legal Notice
All information products included in https://us-cert.gov/ics 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 https://www.us-cert.gov/tlp/ .
1. EXECUTIVE SUMMARY
o CVSS v3 8.1
o ATTENTION: Exploitable remotely/low skill level to exploit
o Vendor: Siemens
o Equipment: Polarion Subversion Webclient
o Vulnerabilities: Improper Neutralization of Script-Related HTML Tags in a
Web Page (Basic XSS), Cross-site Request Forgery (CSRF)
2. RISK EVALUATION
Successful exploitation of these vulnerabilities where an attacker injects
client-side script to induce the victim to issue an HTTP request could lead to
a state-changing operation.
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
The following versions of Siemens Polarion Subversion Webclient are affected:
o Polarion Subversion Webclient, all versions
3.2 VULNERABILITY OVERVIEW
3.2.1 IMPROPER NEUTRALIZATION OF SCRIPT-RELATED HTML TAGS IN A WEB PAGE (BASIC
XSS) CWE-80
The Polarion Subversion Webclient application does not filter user input in a
way that prevents cross-site scripting (XSS). If a user is enticed into passing
specially crafted malicious input to the web client (e.g., by clicking on a
malicious URL with embedded JavaScript), JavaScript code can be returned and
executed by the user's client. Various actions could be triggered by running
malicious JavaScript code.
CVE-2020-15788 has been assigned to this vulnerability. A CVSS v3 base score of
6.1 has been calculated; the CVSS vector string is ( AV:N/AC:L/PR:N/UI:R/S:C/
C:L/I:L/A:N ).
3.2.2 CROSS-SITE REQUEST FORGERY (CSRF) CWE-352
The web interface could allow a CSRF attack if an unsuspecting user is tricked
into accessing a malicious link. Successful exploitation requires user
interaction by a legitimate user, who must be authenticated to the web
interface. A successful attack could allow an attacker to trigger actions via
the web interface that the legitimate user is allowed to perform. This could
allow the attacker to read or modify contents of the web application.
CVE-2020-15789 has been assigned to this vulnerability. A CVSS v3 base score of
8.1 has been calculated; the CVSS vector string is ( AV:N/AC:L/PR:N/UI:R/S:U/
C:H/I:H/A:N ).
3.3 BACKGROUND
o CRITICAL INFRASTRUCTURE SECTORS: Energy
o COUNTRIES/AREAS DEPLOYED: Worldwide
o COMPANY HEADQUARTERS LOCATION: Germany
3.4 RESEARCHER
Li Yifan reported these vulnerabilities to Siemens.
4. MITIGATIONS
Siemens has stated that the tool is considered shareware, distributed "as is,"
and will be no fix as it is no longer supported.
Siemens has identified the following specific workaround and mitigation users
can apply to reduce the risk:
o Do not open unknown links while working on Polarion Subversion Webclient.
As a general security measure, Siemens strongly recommends protecting network
access to devices with appropriate mechanisms. To operate the devices in a
protected IT environment, Siemens recommends configuring the environment
according to Siemens operational guidelines for Industrial Security and
following the recommendations in the product manuals.
For additional information, please refer to Siemens Security Advisory
SSA-436520
CISA also recommends users take the following measures to protect themselves
from social engineering attacks:
o Refer to Recognizing and Avoiding Email Scams for more information on
avoiding email scams.
o Refer to Avoiding Social Engineering and Phishing Attacks for more
information on social engineering attacks.
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 Improving 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
Strategies .
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 these vulnerabilities.
For any questions related to this report, please contact the CISA at:
Email: CISAservicedesk@cisa.dhs.gov
Toll Free: 1-888-282-0870
CISA 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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