CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:C/I:C/A:C
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
AI Score
Confidence
High
EPSS
Percentile
12.6%
Successful exploitation of this vulnerability could allow an attacker to achieve privilege escalation on the web server of certain devices configured by SIMATIC STEP 7 (TIA Portal) due to incorrect handling of the webserver’s user management configuration during downloading.
The following Siemens products are affected:
An attacker could achieve privilege escalation on the web server of certain devices due to an improper access control vulnerability in the engineering system software. The attacker needs to have direct access to the impacted web server.
CVE-2021-42029 has been assigned to this vulnerability. A CVSS v3 base score of 6.4 has been calculated; the CVSS vector string is (AV:L/AC:H/PR:H/UI:R/S:C/C:H/I:L/A:L).
Siemens reported this vulnerability to CISA.
Siemens recommends updating their software to the latest version:
Siemens has identified the following specific workarounds and mitigations users can apply to reduce the risk:
As a general security measure, Siemens strongly recommends protecting network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends users configure the environment according to the Siemens operational guidelines for industrial security and follow the recommendations in the product manuals.
For additional information, please refer to Siemens Security Advisory SSA-350757
CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:
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 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 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.
CISA also recommends users take the following measures to protect themselves from social engineering attacks:
No known public exploits specifically target this vulnerability. This vulnerability is not exploitable remotely. This vulnerability has a high attack complexity.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-42029
cert-portal.siemens.com/operational-guidelines-industrial-security.pdf
cert-portal.siemens.com/productcert/pdf/ssa-350757.pdf
cisasurvey.gov1.qualtrics.com/jfe/form/SV_9n4TtB8uttUPaM6?product=https://www.cisa.gov/news-events/ics-advisories/icsa-22-104-14
cwe.mitre.org/data/definitions/284.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
support.industry.siemens.com/cs/gb/en/view/109775861
support.industry.siemens.com/cs/gb/en/view/109784441
twitter.com/CISAgov
twitter.com/intent/tweet?text=Siemens%20SIMATIC%20STEP%207%20%28TIA%20Portal%29+https://www.cisa.gov/news-events/ics-advisories/icsa-22-104-14
www.cisa.gov/uscert/ics
www.cisa.gov/uscert/ics
www.cisa.gov/uscert/ics/alerts/ICS-ALERT-10-301-01
www.cisa.gov/uscert/ics/recommended-practices
www.cisa.gov/uscert/ics/tips/ICS-TIP-12-146-01B
www.cisa.gov/uscert/ncas/tips/ST04-014
www.cisa.gov/uscert/sites/default/files/publications/emailscams_0905.pdf
www.cisa.gov/uscert/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-22-104-14&title=Siemens%20SIMATIC%20STEP%207%20%28TIA%20Portal%29
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:L/AC:H/PR:H/UI:R/S:C/C:H/I:L/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-22-104-14
www.oig.dhs.gov/
www.usa.gov/
www.whitehouse.gov/
www.youtube.com/@cisagov
mailto:?subject=Siemens%20SIMATIC%20STEP%207%20%28TIA%20Portal%29&body=www.cisa.gov/news-events/ics-advisories/icsa-22-104-14
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:C/I:C/A:C
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
AI Score
Confidence
High
EPSS
Percentile
12.6%