CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:N/I:N/A:C
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
AI Score
Confidence
High
EPSS
Percentile
5.1%
Successful exploitation of these vulnerabilities could allow an attacker with local access to craft special project files that may lead to denial-of-service attacks.
The following Siemens products are affected:
An attacker with local access to the system could cause a denial-of-service condition in the application when it is used to open a specially crafted file. As a result, the application could enter an infinite loop, become unresponsive, and must be restarted to restore the service.
CVE-2021-25673 has been assigned to this vulnerability. A CVSS v3 base score of 5.5 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).
An attacker with local access to the system could cause a denial-of-service condition in the application when it is used to open a specially crafted file. As a result, a NULL pointer deference condition could cause the application to terminate unexpectedly and must be restarted to restore the service.
CVE-2021-25674 has been assigned to this vulnerability. A CVSS v3 base score of 5.5 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).
An attacker with local access to the system could cause a denial-f-service condition in the application when it is used to open a specially crafted file. As a result, a divide by zero operation could occur and cause the application to terminate unexpectedly and must be restarted to restore the service.
CVE-2021-25675 has been assigned to this vulnerability. A CVSS v3 base score of 5.5 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).
Siemens reported these vulnerabilities to CISA.
Siemens has identified the following specific workarounds and mitigations users can apply to reduce risk:
As a general security measure, Siemens recommends protecting network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends configuring the environment according to the Siemens operational guidelines for Industrial Security and following the recommendations in the product manuals.
For additional information, please refer to Siemens Security Advisory SSA-256092
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. These vulnerabilities are not exploitable remotely.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-25673
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-25674
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-25675
cert-portal.siemens.com/operational-guidelines-industrial-security.pdf
cert-portal.siemens.com/productcert/pdf/ssa-256092.pdf
cisasurvey.gov1.qualtrics.com/jfe/form/SV_9n4TtB8uttUPaM6?product=https://www.cisa.gov/news-events/ics-advisories/icsa-21-068-01
cwe.mitre.org/data/definitions/369html
cwe.mitre.org/data/definitions/476.html
cwe.mitre.org/data/definitions/835.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
twitter.com/CISAgov
twitter.com/intent/tweet?text=Siemens%20SIMATIC%20S7-PLCSIM+https://www.cisa.gov/news-events/ics-advisories/icsa-21-068-01
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-21-068-01&title=Siemens%20SIMATIC%20S7-PLCSIM
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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-21-068-01
www.oig.dhs.gov/
www.usa.gov/
www.whitehouse.gov/
www.youtube.com/@cisagov
mailto:?subject=Siemens%20SIMATIC%20S7-PLCSIM&body=www.cisa.gov/news-events/ics-advisories/icsa-21-068-01
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:N/I:N/A:C
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
AI Score
Confidence
High
EPSS
Percentile
5.1%