Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256
===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2018.0995
Advisory (ICSA-18-088-01) WAGO 750 Series
4 April 2018
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: WAGO 750 Series
Publisher: ICS-CERT
Operating System: Network Appliance
Impact/Access: Denial of Service -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2018-8836
Original Bulletin:
https://ics-cert.us-cert.gov/advisories/ICSA-18-088-01
- --------------------------BEGIN INCLUDED TEXT--------------------
Advisory (ICSA-18-088-01) WAGO 750 Series
Original release date: March 29, 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 5.3
ATTENTION: Exploitable remotely/low skill level to exploit.
Vendor: WAGO
Equipment: 750 Series
Vulnerability: Improper Resource Shutdown or Release
AFFECTED PRODUCTS
The following versions of 750 series PLC are affected:
750-880 firmware version 10 and prior,
750-881 firmware version 10 and prior,
750-852 firmware version 10 and prior,
750-882 firmware version 10 and prior,
750-885 firmware version 10 and prior,
750-831 firmware version 10 and prior,
750-889 firmware version 10 and prior, and
750-829 firmware version 10 and prior.
IMPACT
Successful exploitation of this vulnerability could allow a denial-of-service
condition affecting the ability of the device to establish connections to
commissioning and service software tools.
MITIGATION
WAGO has released new firmware addressing this vulnerability that can be
obtained by contacting WAGO support via email at support@wago.com (link sends
e-mail).
If updating the firmware is not feasible WAGO recommends that users disable
the WAGO Service Communication via WBM or limit the access to Ports 6626 and
2455/TCP/IP to trusted devices.
For more information see WAGOs security advisory:
Vulnerability-in-the-WAGO-Ethernet-TCP-IP-driver.pdf (link is external)
NCCIC recommends 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.
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 web site.
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 this vulnerability.
VULNERABILITY OVERVIEW
IMPROPER RESOURCE SHUTDOWN OR RELEASE CWE-404
A remote attack may take advantage of an improper implementation of the 3 way
handshake during a TCP connection affecting the communications with commission
and service tools. Specially crafted packets may also be sent to Port
2455/TCP/IP, used in Codesys management software, which may result in a
denial-of-service condition of communications with commissioning and service
tools.
CVE-2018-8836 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:N/A:L).
RESEARCHER
Younes Dragoni of Nozomi Networks reported the vulnerability to NCCIC.
BACKGROUND
Critical Infrastructure Sectors: Commercial Facilities, Critical
Manufacturing, Energy, and Transportation Systems
Countries/Areas Deployed: Worldwide
Company Headquarters Location: United States, Germany, Switzerland, Poland,
China, and India
- --------------------------END INCLUDED TEXT--------------------
You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.
NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members. As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.
NOTE: This is only the original release of the security bulletin. It may
not be updated when updates to the original are made. If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.
Contact information for the authors of the original document is included
in the Security Bulletin above. If you have any questions or need further
information, please contact them directly.
Previous advisories and external security bulletins can be retrieved from:
https://www.auscert.org.au/bulletins/
===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072
Internet Email: auscert@auscert.org.au
Facsimile: (07) 3365 7031
Telephone: (07) 3365 4417 (International: +61 7 3365 4417)
AusCERT personnel answer during Queensland business hours
which are GMT+10:00 (AEST).
On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967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=AuMi
-----END PGP SIGNATURE-----