5 Medium
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
5.3 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
LOW
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
5.5 Medium
AI Score
Confidence
High
0.003 Low
EPSS
Percentile
69.2%
**ATTENTION:**Exploitable remotely/low skill level to exploit.
Vendor: WAGO
Equipment: 750 Series
Vulnerability: Improper Resource Shutdown or Release
The following versions of 750 series PLC are affected:
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.
WAGO has released new firmware addressing this vulnerability that can be obtained by contacting WAGO support via email at [email protected].
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 WAGO’s security advisory:
Vulnerability-in-the-WAGO-Ethernet-TCP-IP-driver.pdf
NCCIC recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:
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.
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).
Younes Dragoni of Nozomi Networks reported the vulnerability to NCCIC.
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
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-8836
cwe.mitre.org/data/definitions/404.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
twitter.com/CISAgov
twitter.com/intent/tweet?text=WAGO%20750%20Series+https://www.cisa.gov/news-events/ics-advisories/icsa-18-088-01
www.dhs.gov
www.dhs.gov/foia
www.dhs.gov/performance-financial-reports
www.facebook.com/CISA
www.facebook.com/sharer/sharer.php?u=https://www.cisa.gov/news-events/ics-advisories/icsa-18-088-01&title=WAGO%20750%20Series
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
www.instagram.com/cisagov
www.linkedin.com/company/cybersecurity-and-infrastructure-security-agency
www.linkedin.com/sharing/share-offsite/?url=https://www.cisa.gov/news-events/ics-advisories/icsa-18-088-01
www.oig.dhs.gov/
www.surveymonkey.com/r/CISA-cyber-survey?product=https://www.cisa.gov/news-events/ics-advisories/icsa-18-088-01
www.usa.gov/
www.wago.com/medias/Vulnerability-in-the-WAGO-Ethernet-TCP-IP-driver.pdf?context=bWFzdGVyfHJvb3R8MjgxNDk0fGFwcGxpY2F0aW9uL3BkZnxoOTcvaDhkLzkxNTAyMjMyMjA3NjYucGRmfGRlNWQ4ODc0NTE5M2UyNTUwNTIyNDRlOWFkNWI2YjNkMzg0YTVhYzlmYTBjNzM4MDdmNmYzOTM5M2ZlMGEzNzE
www.whitehouse.gov/
www.youtube.com/@cisagov
mailto:?subject=WAGO%20750%20Series&body=www.cisa.gov/news-events/ics-advisories/icsa-18-088-01
5 Medium
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
5.3 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
LOW
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
5.5 Medium
AI Score
Confidence
High
0.003 Low
EPSS
Percentile
69.2%