ESB-2017.1732 - [Appliance] Schweitzer Engineering Laboratories SEL-3620 and SEL-3622: Reduced security - Remote/unauthenticated 2017-07-13

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             AUSCERT External Security Bulletin Redistribution

      Schweitzer Engineering Laboratories, Inc. SEL-3620 and SEL-3622
                               13 July 2017


        AusCERT Security Bulletin Summary

Product:           Schweitzer Engineering Laboratories SEL-3620
                   Schweitzer Engineering Laboratories SEL-3622
Publisher:         ICS-CERT
Operating System:  Network Appliance
Impact/Access:     Reduced Security -- Remote/Unauthenticated
Resolution:        Patch/Upgrade
CVE Names:         CVE-2017-7928  

Original Bulletin:

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Advisory (ICSA-17-192-06)

Schweitzer Engineering Laboratories, Inc. SEL-3620 and SEL-3622

Original release date: July 11, 2017

Legal Notice

All information products included in 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

CVSS v3 7.2

ATTENTION: Remotely exploitable/Low skill level to exploit.

Vendor: Schweitzer Engineering Laboratories, Inc. (SEL)

Equipment: SEL-3620, SEL-3622

Vulnerability: Improper Access Control


The following versions of SEL-3620 and SEL-3622, an Ethernet Security Gateway,
are affected:

Security Gateway Versions R202 and,

R203, R203-V1, R203-V2 and,

R204, R204-V1.


This behavior could result in unauthorized communications through the SEL-3620
and SEL-3622 to configured NAT port forwarding destinations.


SEL has determined that, when NAT port forwarding is not used, all routed 
traffic is filtered properly through the firewall access control lists. If NAT
port forwarding is required, SEL recommends that users of affected products 
contact their SEL Sales Representative or Customer Service Representative to 
obtain a no-cost firmware upgrade CD-ROM packet including upgrade 

Contact can be made at the following location: (link is external)

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.

No known public exploits specifically target this vulnerability.



The device does not properly enforce access control while configured for NAT 
port forwarding, which may allow for unauthorized communications to downstream

CVE-2017-7928 has been assigned to this vulnerability. A CVSS v3 base score of
7.2 has been assigned; the CVSS vector string is 


Jason Holcomb with Revolutionary Security discovered the vulnerability and has
tested the patch.


Critical Infrastructure Sector: Energy

Countries/Areas Deployed: Worldwide

Company Headquarters Location: Pullman, Washington

Contact Information

For any questions related to this report, please contact ICS-CERT at:

Email: (link sends e-mail)

Toll Free: 1-877-776-7585

International Callers: (208) 526-0900

For industrial control systems security information and incident reporting:

ICS-CERT continuously strives to improve its products and services. You can 
help by choosing one of the links below to provide feedback about this 

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