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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2021.3306 Advisory (icsa-21-278-02) Emerson WirelessHART Gateway 6 October 2021 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Emerson WirelessHART Gateway Publisher: ICS-CERT Operating System: Network Appliance Impact/Access: Root Compromise -- Existing Account Execute Arbitrary Code/Commands -- Existing Account Overwrite Arbitrary Files -- Existing Account Access Confidential Data -- Existing Account Resolution: Patch/Upgrade CVE Names: CVE-2021-85337 CVE-2021-81019 CVE-2021-24769 CVE-2021-22439 CVE-2021-10073 CVE-2021-03554 Original Bulletin: https://us-cert.cisa.gov/ics/advisories/icsa-21-278-02 - --------------------------BEGIN INCLUDED TEXT-------------------- ICS Advisory (ICSA-21-278-02) Emerson WirelessHART Gateway Original release date: October 05, 2021 Legal Notice All information products included in https://us-cert.cisa.gov/ics are provided "as is" for informational purposes only. The Department of Homeland Security (DHS) does not provide any warranties of any kind regarding any information contained within. DHS does not endorse any commercial product or service, referenced in this product or otherwise. Further dissemination of this product is governed by the Traffic Light Protocol (TLP) marking in the header. For more information about TLP, see https://us-cert.cisa.gov/tlp/ . 1. EXECUTIVE SUMMARY o CVSS v3 8.0 o ATTENTION: Exploitable remotely/low attack complexity o Vendor: Emerson o Equipment: WirelessHART Gateway o Vulnerabilities: Missing Authentication for Critical Function, Improper Input Validation, Improper Limitation of a Pathname to a Restricted Directory, Write-what-where Condition, Improper Neutralization of Special Elements used in an OS Command, Exposure of Sensitive Information to an Unauthorized Actor 2. RISK EVALUATION Successful exploitation of these vulnerabilities by an authenticated user can allow root level arbitrary write permission, which can lead to remote code execution. 3. TECHNICAL DETAILS 3.1 AFFECTED PRODUCTS The following versions of Emerson WirelessHART Gateway network communication devices are affected: o WirelessHART 1410 Gateway: All versions prior to v4.7.94 o WirelessHART 1410D Gateway: All versions prior to v4.7.94 o WirelessHART 1420 Gateway: All versions prior to v4.7.94 3.2 VULNERABILITY OVERVIEW 3.2.1 MISSING AUTHENTICATION FOR CRITICAL FUNCTION CWE-306 The affected product is vulnerable to a missing permission validation on system backup restore, which could lead to account take over and unapproved settings change. CVE-2021-85337 has been assigned to this vulnerability. A CVSS v3 base score of 8.0 has been assigned; the CVSS vector string is ( AV:N/AC:L/PR:L/UI:R/S:U/C:H/ I:H/A:H ). 3.2.2 IMPROPER INPUT VALIDATION CWE-20 The affected product is vulnerable to improper input validation in the restore file. This enables an attacker to provide malicious config files to replace any file on disk. CVE-2021-03554 has been assigned to this vulnerability. A CVSS v3 base score of 8.0 has been assigned; the CVSS vector string is ( AV:N/AC:L/PR:L/UI:R/S:U/C:H/ I:H/A:H ). 3.2.3 IMPROPER LIMITATION OF A PATHNAME TO A RESTRICTED DIRECTORY CWE-22 The affected product is vulnerable to directory traversal due to mishandling of provided backup folder structure. CVE-2021-24769 has been assigned to this vulnerability. A CVSS v3 base score of 8.0 has been assigned; the CVSS vector string is ( AV:N/AC:L/PR:L/UI:R/S:U/C:H/ I:H/A:H ). 3.2.4 WRITE-WHAT-WHERE CONDITION CWE-123 The affected product is vulnerable to a unsanitized extract folder for system configuration. A low-privileged user can leverage this logic to overwrite the settings and other key functionality. CVE-2021-22439 has been assigned to this vulnerability. A CVSS v3 base score of 8.0 has been assigned; the CVSS vector string is ( AV:N/AC:L/PR:L/UI:R/S:U/C:H/ I:H/A:H ). 3.2.5 IMPROPER NEUTRALIZATION OF SPECIAL ELEMENTS USED IN AN OS COMMAND CWE-78 The affected product is vulnerable to a parameter injection via passphrase, which enables the attacker to supply uncontrolled input. CVE-2021-81019 has been assigned to this vulnerability. A CVSS v3 base score of 8.0 has been assigned; the CVSS vector string is ( AV:N/AC:L/PR:L/UI:R/S:U/C:H/ I:H/A:H ). 3.2.6 EXPOSURE OF SENSITIVE INFORMATION TO AN UNAUTHORIZED ACTOR CWE-200 The affected product is vulnerable to a disclosure of peer username and password by allowing all users access to read global variables. CVE-2021-10073 has been assigned to this vulnerability. A CVSS v3 base score of 8.0 has been assigned; the CVSS vector string is ( AV:N/AC:L/PR:L/UI:R/S:U/C:H/ I:H/A:H ). 3.3 BACKGROUND o CRITICAL INFRASTRUCTURE SECTORS: Chemical, Critical Manufacturing, Dams, Energy, Food and Agriculture, Healthcare and Public Health, Transportation Systems, Water and Wastewater Systems o COUNTRIES/AREAS DEPLOYED: Worldwide o COMPANY HEADQUARTERS LOCATION: United States 3.4 RESEARCHER Amir Preminger of Claroty reported these vulnerabilities to CISA. 4. MITIGATIONS Emerson recommends upgrading to v4.7.105 to address these vulnerabilities. Users can visit the Emerson Gate Firmware site for and download instructions. If affected users do not yet have a free Guardian account, please see the updated Emerson Gateway Firmware download process by following the link above and viewing the download guide. CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should: o Minimize network exposure for all control system devices and/or systems, and ensure that they are not accessible from the Internet . o Locate control system networks and remote devices behind firewalls, and isolate them from the business network. o When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as its connected devices. 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. For any questions related to this report, please contact the CISA at: Email: CISAservicedesk@cisa.dhs.gov Toll Free: 1-888-282-0870 CISA continuously strives to improve its products and services. You can help by choosing one of the links below to provide feedback about this product. - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. 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It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: https://www.auscert.org.au/bulletins/ =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBYV0O6eNLKJtyKPYoAQiTkw/+NpU7ScR0ykOlEKnVRDniJfe14/XbF+bg SmWx8PnXl8KmS2JUsIJGaTWvykvfKImd54M6+tXbofvLzt69lCn6ga8izfEf5FkI qvYWz9XvJ4/I1L+HPilfKQlKcJn3mWkE3h1kU8Eiy2RqEtYGxFK6qx4TShZF4gA6 KAhSStlreTvxpQzoL2SUhjXgA3j/PTDq9dgYhTYimMI2TLwvJUGfiAJoqqKCfwcy VIuMyaKGdUJqa14ANei2rw95s/30UuF4HVIag/S9ygqqeDrTstPUr+m7l+rPe4DB QDVluwDVrV7q5Ztj9ELqm150/hwtniGH0N5FVrJhaWb/VPvZDAtJISRmwS2Pd9i+ dNPWZGO89LAQel4ZFNat6dsMu7wuS0aQek2rE0zrsD6jUZBmX7eg8fCr7uRIPyHR PEscgqOgiXdzQ9MuwPbTMKLCQmkFXptU49iBIBwOq+5w1O87f1CvX/kYSA828xwC 80KE4xy68m+Zw8KfVNPG2Rbi2+PRvZ7E+EjCv5rL1cwVqT4PiVqayWJHX8wDLwlC Sa1k0tZG5BFuGdVHsIjmXRuK4/69WDb/B4DgF4+hUSqXRpPVQXw357/xgxFn4ghO e4zAgtsl/hsJJ9TYkzJbbRUh+TPMLf7paHoz4es3KCT79P/cssrJShqIbdLS4lS/ 0gniDXUJ2bc= =w9xo -----END PGP SIGNATURE-----