CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:L/AC:L/Au:N/C:P/I:P/A:P
CVSS3
Attack Vector
PHYSICAL
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
AI Score
Confidence
High
EPSS
Percentile
59.6%
The updated advisory is a follow-up to the original advisory titled ICSA-21-266-01 Trane Symbio that was published on September 23, 2021, to the ICS webpage on us-cert.cisa.gov.
--------- Begin Update B Part 1 of 1 --------
Successful exploitation of this vulnerability could allow a user to execute arbitrary code on the controller.
--------- End Update B Part 1 of 1 --------
The following Trane building automation products deployed on the following HVAC equipment are affected:
Symbio 700:
Symbio 800:
The affected controllers do not properly sanitize the input containing code syntax. As a result, an attacker could craft code to alter the intended controller flow of the software.
CVE-2021-38448 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been calculated; the CVSS vector string is (AV:P/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:H).
Trane reported this vulnerability to CISA.
Affected users should contact a Trane office to make arrangements to install updated firmware or to request additional information. Please reference Trane service database number HUB-205962 when contacting Trane. Trane recommends the applications below be updated to the versions listed below.
Symbio 700:
Symbio 800:
In addition to the specific recommendations above, Trane continues to recommend the following best practices as an additional protection against this and other controller vulnerabilities:
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.
No known public exploits specifically target this vulnerability. This vulnerability is not exploitable remotely.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-38448
www.trane.com/commercial/north-america/us/en.html
cisasurvey.gov1.qualtrics.com/jfe/form/SV_9n4TtB8uttUPaM6?product=https://www.cisa.gov/news-events/ics-advisories/icsa-21-266-01
cwe.mitre.org/data/definitions/94.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
twitter.com/CISAgov
twitter.com/intent/tweet?text=Trane%20Symbio%20%28Update%20B%29+https://www.cisa.gov/news-events/ics-advisories/icsa-21-266-01
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/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
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www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:C/C:L/I:H/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-21-266-01
www.oig.dhs.gov/
www.usa.gov/
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www.youtube.com/@cisagov
mailto:?subject=Trane%20Symbio%20%28Update%20B%29&body=www.cisa.gov/news-events/ics-advisories/icsa-21-266-01
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:L/AC:L/Au:N/C:P/I:P/A:P
CVSS3
Attack Vector
PHYSICAL
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
AI Score
Confidence
High
EPSS
Percentile
59.6%