Schneider Electric Wonderware Historian Client

CVSS v3 6.6

ATTENTION: Low skill level to exploit.

Vendor: Schneider Electric

Equipment: Wonderware Historian Client

Vulnerability: Improper XML Parser Configuration

AFFECTED PRODUCTS

The following versions of Wonderware Historian Client, an analysis and reporting software, are affected:

• Wonderware Historian Client 2014 R2 SP1 and prior.

IMPACT

Successful exploitation of this vulnerability could allow a malicious entity to cause denial of service of trend display or to disclose arbitrary files from the local file system to a malicious web site.

MITIGATION

Schneider Electric recommends that users of Wonderware Historian Client 2014 R2 SP1 apply update HC_SecurityHF_10.6.13100. Users of older versions of Wonderware Historian Client are also affected and should first upgrade to Wonderware Historian Client 2014 R2 SP1 and then apply HC_SecurityHF_10.6.13100.

Users of Wonderware Historian Client can login at the following support web site to download the upgrade:

https://gcsresource.invensys.com/tracking/ConfirmDownload.aspx?id=22409

Schneider Electric has issued Security Bulletin LFSEC00000120, which contains additional information:

http://software.schneider-electric.com/support/cyber-security-updates/

NCCIC/ICS-CERT recommends that users take defensive measures to minimize the risk of exploitation of this vulnerability. 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.

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.

In addition, ICS-CERT recommends that users take the following measures to protect themselves from social engineering attacks:

1. Do not click web links or open unsolicited attachments in email messages.
2. Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams.
3. Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.

No known public exploits specifically target this vulnerability.

VULNERABILITY OVERVIEW

An improperly restricted XML parser may allow an attacker to enter malicious input through the application which could cause a denial of service or disclose file contents from a server or connected network.

CVE-2017-7907 has been assigned to this vulnerability. A CVSS v3 base score of 6.6 has been assigned; the CVSS vector string is (AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:H).

RESEARCHER

Andrey Zhukov from USSC reported this vulnerability and has tested the patch.

BACKGROUND

Critical Infrastructure Sector(s): Critical Manufacturing, Energy, Healthcare and Public Health, Water and Wastewater Systems

Countries/Areas Deployed: Worldwide

Company Headquarters Location: Paris, France

• Schneider Electric