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AUSCERT External Security Bulletin Redistribution
Advisory (icsa-22-228-06) Emerson Proficy Machine Edition
17 August 2022
AusCERT Security Bulletin Summary
Product: Emerson Proficy Machine Edition
Operating System: Network Appliance
CVE Names: CVE-2022-2793 CVE-2022-2792 CVE-2022-2791
CVE-2022-2790 CVE-2022-2789 CVE-2022-2788
Comment: CVSS (Max): 5.9 CVE-2022-2793 (CVSS:3.0/AV:P/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H)
CVSS Source: ICS-CERT
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ICS Advisory (ICSA-22-228-06)
Emerson Proficy Machine Edition
Original release date: August 16, 2022
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
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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
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1. EXECUTIVE SUMMARY
o CVSS v3 9.3
o ATTENTION: Exploitable remotely/Low attack complexity
o Vendor: Emerson
o Equipment: Proficy Machine Edition
o Vulnerabilities: Missing Support for Integrity Check, Improper Access
Control, Unrestricted Upload of File with Dangerous Type, Improper
Verification of Cryptographic Signature, Insufficient Verification of Data
Authenticity, Path Traversal: '\..\filename'
2. RISK EVALUATION
Successful exploitation of these vulnerabilities could allow for remote hidden
code execution on the connected programmable logic controller (PLC) and for
malicious files to be uploaded from the PLC to connected workstations.
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
The following versions of Proficy Machine Edition, an engineering workstation
that is part of the PACSystems control system software platform, are affected:
o Proficy Machine Edition Version 9.80 and prior
3.2 VULNERABILITY OVERVIEW
3.2.1 MISSING SUPPORT FOR INTEGRITY CHECK CWE-353
Proficy Machine Edition Version 9.00 and prior has no authentication or
authorization of data packets after establishing a connection for the SRTP
CVE-2022-2793 has been assigned to this vulnerability. A CVSS v3 base score of
5.9 has been assigned; the CVSS vector string is ( AV:P/AC:L/PR:N/UI:R/S:U/C:N/
3.2.2 IMPROPER ACCESS CONTROL CWE-284
Proficy Machine Edition Version 9.00 and prior stores project data in a
directory with improper access control lists.
CVE-2022-2792 has been assigned to this vulnerability. A CVSS v3 base score of
6.6 has been assigned; the CVSS vector string is ( AV:L/AC:L/PR:L/UI:R/S:U/C:N/
3.2.3 UNRESTRICTED UPLOAD OF FILE WITH DANGEROUS FILE TYPE CWE-434
Proficy Machine Edition Version 9.00 and prior will upload any file written
into the PLC logic folder to the connected PLC.
CVE-2022-2791 has been assigned to this vulnerability. A CVSS v3 base score of
5.9 has been assigned; the CVSS vector string is ( AV:L/AC:L/PR:L/UI:R/S:C/C:N/
3.2.4 IMPROPER VERIFICATION OF CRYPTOGRAPHIC SIGNATURE CWE-347
Proficy Machine Edition Version 9.00 and prior does not properly verify
compiled logic (PDT files) and data blocks data (BLD/BLK files).
CVE-2022-2790 has been assigned to this vulnerability. A CVSS v3 base score of
5.9 has been assigned; the CVSS vector string is ( AV:L/AC:L/PR:L/UI:R/S:C/C:N/
3.2.5 INSUFFICIENT VERIFICATION OF DATA AUTHENTICITY CWE-345
Proficy Machine Edition Version 9.00 and prior can display logic that is
different than the compiled logic.
CVE-2022-2789 has been assigned to this vulnerability. A CVSS v3 base score of
4.7 has been assigned; the CVSS vector string is ( AV:L/AC:H/PR:N/UI:R/S:U/C:N/
3.2.6 PATH TRAVERSAL: '\..\FILENAME' CWE-29
Proficy Machine Edition Version 9.80 and prior is vulnerable to a ZipSlip
attack through an upload procedure which enables attackers to implant a
malicious .BLZ file on the PLC. The file can transfer through the engineering
station onto Windows in a way that executes the malicious code.
CVE-2022-2788 has been assigned to this vulnerability. A CVSS v3 base score of
9.3 has been assigned; the CVSS vector string is ( AV:N/AC:L/PR:N/UI:R/S:C/C:N/
o CRITICAL INFRASTRUCTURE SECTORS: Commercial Facilities, Critical
Manufacturing, Dams, Defense Industrial Base, Energy, Food and Agriculture,
Government Facilities, Information Technology, Transportation Systems,
Water and Wastewater Systems
o COUNTRIES/AREAS DEPLOYED: Worldwide
o COMPANY HEADQUARTERS LOCATION: United States
Sharon Brizinov of Claroty Research reported these vulnerabilities to CISA.
Emerson recommends users take the following measures to mitigate the risks
associated with each of the identified vulnerabilities:
o CVE-2022-2793: SRTP and SNP protocols support cryptographically secure
authentication using the SRP-6a protocol, a feature which Emerson
recommends users employ. Affected devices currently support encrypted
authentication for session establishment and when escalating privileges;
additional encryption features will be added over time.
o CVE-2022-2792: Emerson plans to fix this vulnerability in a future version.
Emerson recommends users ensure they are using the latest version of PAC
Machine Edition and employ good physical security of devices and
o CVE-2022-2791: Emerson recommends operators of the affected devices be well
verified and restrict which users can upload files. The affected devices do
not have any file verification systems for checking the files that have
o CVE-2022-2790: See recommendations for CVE-2022-2791.
o CVE-2022-2789: See recommendations for CVE-2022-2791.
o CVE-2022-2788: See recommendations for CVE-2022-2791. Emerson recommends
Proficy Machine Edition be installed as an administrator, but run as a
non-administrator, unless necessary for specific functions. Users should
ensure PLCs are not programmed using an untrusted network; PLCs should be
programmed using a flat/bridged network. Users should also enable
authentication on the PLCs.
For additional details on any of these recommendations, see Emerson's security
CISA recommends users take defensive measures to minimize the risk of
exploitation of this vulnerability these vulnerabilities. Specifically, users
o Minimize network exposure for all control system devices and/or systems,
and ensure they are not accessible from the Internet .
o Locate control system networks and remote devices behind firewalls and
isolate them from business networks.
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 at cisa.gov/ics . Several CISA products detailing cyber
defense best practices are available for reading and download, including
Improving Industrial Control Systems Cybersecurity with Defense-in-Depth
Additional mitigation guidance and recommended practices are publicly available
on the ICS webpage at cisa.gov/ics in the technical information paper,
ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation
Organizations observing suspected malicious activity should follow established
internal procedures and report findings to CISA for tracking and correlation
against other incidents.
Social Engineering ATTACK CODE
CISA also recommends users take the following measures to protect themselves
from social engineering attacks:
o Do not click web links or open attachments in unsolicited email messages.
o Refer to Recognizing and Avoiding Email Scams for more information on
avoiding email scams.
o Refer to Avoiding Social Engineering and Phishing Attacks for more
information on social engineering attacks.
No known public exploits specifically target these vulnerabilities.
For any questions related to this report, please contact the CISA at:
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.
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