Rockwell Automation RSLinx Classic and FactoryTalk Linx Gateway Privilege Escalation

Title: Rockwell Automation RSLinx Classic and FactoryTalk Linx Gateway Privilege Escalation
Advisory ID: ZSL-2018-5473
Type: Local
Impact: Privilege Escalation
Risk: (3/5)
Release Date: 10.06.2018
RSLinx Classic is a software platform that allows Logix5000 Programmable Automation Controllers to connect to a wide variety of Rockwell Software applications, and FactoryTalk Linx Gateway is a software that provides an Open Platform Communications (OPC) Unified Architecture (UA) server interface to allow the delivery of information from Rockwell Software applications to Allen-Bradley controllers.
The application suffers from an unquoted search path issue impacting the service 'dnwhodisp' for Windows deployed as part of RSLinx and FactoryTalk. This could potentially allow an authorized but non-privileged local user to execute arbitrary code with elevated privileges on the system. A successful attempt would require the local user to be able to insert their code in the system root path undetected by the OS or other security applications where it could potentially be executed during application startup or reboot. If successful, the local user's code would execute with the elevated privileges of the application.
Rockwell Automation, Inc. -
Affected Version
Rockwell Automation RSLinx Classic 3.90.01
Rockwell Automation RSLinx Classic 3.73.00
Rockwell Automation RSLinx Classic 3.72.00
Rockwell Automation RSLinx Classic 2.58.00
Rockwell Automation FactoryTalk Linx Gateway 3.90.00
Tested On
Microsoft Windows 7 Professional SP1 (EN)
Vendor Status
[11.12.2017] Vulnerability discovered.
[11.12.2017] Vendor contacted.
[11.12.2017] Vendor responds asking more details, providing PGP key.
[11.12.2017] Sent details to the vendor.
[19.12.2017] Asked vendor for status update.
[20.12.2017] Vendor is investigating the issue.
[27.02.2018] Asked vendor for status update.
[27.02.2018] Vendor verifies the issues, working on a fix.
[13.03.2018] Asked vendor for status update.
[04.06.2018] Vendor replies with release information. Provides fixed version RSLinx Classic 4.00.01 and FactoryTalk Linx Gateway 6.00.00 to its customers.
[06.06.2018] Vendor sends draft advisory to ZSL.
[07.06.2018] Replied to the vendor.
[10.06.2018] Coordinated public security advisory released.
Vulnerability discovered by Gjoko Krstic - <>
[10.06.2018] - Initial release
[22.06.2018] - Added reference [6], [7], [8], [9] and [10]
[31.01.2024] - Added reference [11]
Zero Science Lab