Multiple Siemens EN100 Ethernet Modules SSA-418979 Multiple Security Vulnerabilities

Risk

High

Date Discovered

December 10, 2019

Description

Multiple Siemens EN100 Ethernet Modules are prone to multiple security vulnerabilities. An attacker may leverage these issues to execute arbitrary code, using directory-traversal sequences ('../') to retrieve sensitive information and execute arbitrary script code in the browser of an unsuspecting user in the context of the affected site. This may allow the attacker to steal cookie-based authentication credentials and launch other attacks. The following Siemens EN100 Ethernet Modules are affected: EN100 Ethernet module IEC 61850 versions prior to 4.37 are vulnerable EN100 Ethernet module PROFINET IO is vulnerable EN100 Ethernet module Modbus TCP is vulnerable EN100 Ethernet module DNP3 is vulnerable EN100 Ethernet module IEC104 is vulnerable

Technologies Affected

  • Siemens EN100 Ethernet module DNP3
  • Siemens EN100 Ethernet module IEC 104
  • Siemens EN100 Ethernet module IEC 61850
  • Siemens EN100 Ethernet module Modbus TCP
  • Siemens EN100 Ethernet module PROFINET IO

Recommendations

Block external access at the network boundary, unless external parties require service.
Filter access to the affected computer at the network boundary if global access isn't needed. Restricting access to only trusted computers and networks might greatly reduce the likelihood of a successful exploit.

Run all software as a nonprivileged user with minimal access rights.
Attackers may successfully exploit client flaws in the browser through a cross-site scripting vulnerability. When possible, run client software as regular user accounts with limited access to system resources. This may limit the immediate consequences of client-side vulnerabilities.

Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to detect and block attacks and anomalous activity such as requests containing suspicious URI sequences. Since the webserver may log such requests, review logs regularly.

Do not follow links provided by unknown or untrusted sources.
Web users should be cautious about following links to websites that are provided by unfamiliar or suspicious sources. Filtering HTML from emails may help remove a possible vector for transmitting malicious links to users.

Set web browser security to disable the execution of script code or active content.
Since exploiting a cross-site scripting issue often requires malicious script code to run in browsers, consider disabling script code and active content support within a client browser as a way to prevent a successful exploit. Note that this mitigation tactic might adversely affect legitimate sites that rely on the execution of browser-based script code.

Updates are available. Please see the references or vendor advisory for more information.

References

Credits

The vendor reported these issues.


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