CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:M/Au:N/C:P/I:P/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
AI Score
Confidence
High
EPSS
Percentile
44.3%
This updated advisory is a follow-up to the original advisory titled ICSA-17-243-02 Siemens LOGO! that was published August 31, 2017, on the ICS webpage on us-cert.cisa.gov.
Successful exploitation of these vulnerabilities could allow an attacker to hijack existing web sessions.
Siemens reports the vulnerabilities affect the following LOGO! devices:
--------- Begin Update A Part 1 of 2 ---------
--------- End Update A Part 1 of 2 ---------
An attacker with network access to the integrated web server on Port 80/TCP could obtain the session ID of an active user session. A user must be logged in to the web interface. Siemens recommends that users use the integrated web server on Port 80/TCP only in trusted networks.
CVE-2017-12734 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).
An attacker who performs a man-in-the-middle attack between the LOGO! and other devices could potentially decrypt and modify network traffic.
CVE-2017-12735 has been assigned to this vulnerability. A CVSS v3 base score of 7.4 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N).
Maxim Rupp discovered one of these two vulnerabilities.
Siemens provides LOGO!8 BM FS-05 with firmware Version 1.81.2, which fixes the first Insufficiently Protected Credentials vulnerability.
--------- Begin Update A Part 2 of 2 ---------
Siemens recommends users update to v8.3 to mitigate the Man-in-the-Middle vulnerability.
NOTE: To update, a new hardware version is required.
Siemens has identified the following specific workarounds and mitigations users can apply to reduce risk:
--------- End Update A Part 2 of 2 ---------
As a general security measure, Siemens strongly recommends protecting network access to the devices with appropriate mechanisms. Siemens advises configuring the environment according to Siemens operational guidelines to run the devices in a protected IT environment.
For more information on these vulnerabilities and more detailed mitigation instructions, please see Siemens Security Advisory SSA-087240
CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. 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.cisa.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.cisa.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.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2017-12734
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2017-12735
www.siemens.com/cert/en/cert-security-advisories.htm
cisasurvey.gov1.qualtrics.com/jfe/form/SV_9n4TtB8uttUPaM6?product=https://www.cisa.gov/news-events/ics-advisories/icsa-17-243-02
cwe.mitre.org/data/definitions/300.html
cwe.mitre.org/data/definitions/522.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
support.industry.siemens.com/cs/us/en/view/109741041
support.industry.siemens.com/cs/ww/en/view/109783346/
twitter.com/CISAgov
twitter.com/intent/tweet?text=Siemens%20LOGO%21%20%28Update%20A%29+https://www.cisa.gov/news-events/ics-advisories/icsa-17-243-02
us-cert.cisa.gov/ics
us-cert.cisa.gov/ics
us-cert.cisa.gov/ics/recommended-practices
us-cert.cisa.gov/ics/tips/ICS-TIP-12-146-01B
us-cert.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf
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-17-243-02&title=Siemens%20LOGO%21%20%28Update%20A%29
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
www.industry.siemens.com/topics/global/en/industrial-security/Pages/default.aspx
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-17-243-02
www.oig.dhs.gov/
www.siemens.com/cert/operational-guidelines-industrial-security
www.usa.gov/
www.whitehouse.gov/
www.youtube.com/@cisagov
mailto:?subject=Siemens%20LOGO%21%20%28Update%20A%29&body=www.cisa.gov/news-events/ics-advisories/icsa-17-243-02
CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:M/Au:N/C:P/I:P/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
AI Score
Confidence
High
EPSS
Percentile
44.3%