9.8 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.3 High
AI Score
Confidence
High
7.5 High
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:P/I:P/A:P
0.019 Low
EPSS
Percentile
88.5%
--------- Begin Update A Part 1 of 5 ---------
This advisory was previously released with a set of Siemens products considered to be affected. Following further investigation by the Siemens’ team, it was determined all products previously advised are not affected by any vulnerability listed in this advisory or Siemens Security Advisory SSA-478893
--------- End Update A Part 1 of 5 ---------
This updated advisory is a follow-up to the original advisory titled ICSA-20-343-08 Siemens Products using TightVNC that was published December 8, 2020, to the ICS webpage on us-cert.cisa.gov.
--------- Begin Update A Part 2 of 5 ---------
All products listed in the original advisory associated with ICSA-20-343-08 Siemens Products using TightVNC are unaffected by TightVNC vulnerabilities.
--------- End Update A Part 2 of 5 ---------
--------- Begin Update A Part 3 of 5 ---------
Vulnerabilities in TightVNC (v1.X), a remote-control software package, do not affect the following Siemens products. The previous version of this advisory stated the following products were affected:
--------- End Update A Part 3 of 5 ---------
TightVNC code Version 1.3.10 contains a heap buffer overflow in rfbServerCutText handler, which can potentially result in code execution. The attack appears to be exploitable via network connectivity.
CVE-2019-15678 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
TightVNC code Version 1.3.10 contains a heap buffer overflow in InitialiseRFBConnection function, which can potentially result in code execution. This attack appears to be exploitable via network connectivity.
CVE-2019-15679 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
TightVNC code Version 1.3.10 contains a null pointer dereference in HandleZlibBPP function, which could result in a denial-of-service. This attack appears to be exploitable via network connectivity.
CVE-2019-15680 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:N/I:N/A:H).
TightVNC code Version 1.3.10 contains a global buffer overflow in HandleCoRREBBP macro function, which can potentially result in code execution. This appears to be exploitable via network connectivity.
CVE-2019-8287 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
--------- Begin Update A Part 4 of 5 ---------
Siemens reported this update information to CISA.
--------- End Update A Part 4 of 5 ---------
--------- Begin Update A Part 5 of 5 ---------
This advisory was previously released with a set of Siemens products considered to be affected. Following further investigation by the Siemens’ team, it was determined all products previously advised are not affected by any vulnerability listed in this advisory.
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 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-478893
Contact Siemens or further inquiries on its security vulnerabilities.
--------- End Update A Part 5 of 5 ---------
ISA 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.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-15678
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-15679
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-15680
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-8287
cert-portal.siemens.com/operational-guidelines-industrial-security.pdf
cert-portal.siemens.com/productcert/pdf/ssa-478893.pdf
cwe.mitre.org/data/definitions/120.html
cwe.mitre.org/data/definitions/122.html
cwe.mitre.org/data/definitions/122.html
cwe.mitre.org/data/definitions/476.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
twitter.com/CISAgov
twitter.com/intent/tweet?text=Siemens%20Products%20using%20TightVNC%20%28Update%20A%29+https://www.cisa.gov/news-events/ics-advisories/icsa-20-343-08
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-20-343-08&title=Siemens%20Products%20using%20TightVNC%20%28Update%20A%29
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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: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-20-343-08
www.oig.dhs.gov/
www.siemens.com/cert/advisories
www.surveymonkey.com/r/CISA-cyber-survey?product=https://www.cisa.gov/news-events/ics-advisories/icsa-20-343-08
www.usa.gov/
www.whitehouse.gov/
www.youtube.com/@cisagov
mailto:?subject=Siemens%20Products%20using%20TightVNC%20%28Update%20A%29&body=www.cisa.gov/news-events/ics-advisories/icsa-20-343-08
9.8 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.3 High
AI Score
Confidence
High
7.5 High
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:P/I:P/A:P
0.019 Low
EPSS
Percentile
88.5%