Siemens EN100 Ethernet Module Improper Restriction of Operations Within the Bounds of a Memory Buffer (CVE-2019-13942)

high Tenable OT Security Plugin ID 500352

Synopsis

The remote OT asset is affected by a vulnerability.

Description

A vulnerability has been identified in EN100 Ethernet module DNP3 variant (All versions), EN100 Ethernet module IEC 61850 variant (All versions < V4.37), EN100 Ethernet module IEC104 variant (All versions), EN100 Ethernet module Modbus TCP variant (All versions), EN100 Ethernet module PROFINET IO variant (All versions). An unauthorized user could exploit a buffer overflow vulnerability in the webserver. Specially crafted packets sent could cause a Denial-of-Service condition and if certain conditions are met, the affected devices must be restarted manually to fully recover. At the time of advisory publication no public exploitation of this security vulnerability was known.

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Solution

The following text was originally created by the Cybersecurity and Infrastructure Security Agency (CISA). The original can be found at CISA.gov.

Siemens has released updates for several affected products, is working on updates for the remaining affected products, and recommends specific countermeasures until fixes are available.

- EN100 Ethernet module for IEC 61850: Update to v4.37

For all other affected devices, Siemens recommends users block access to Port 80/TCP and 443/TCP (e.g., with an external firewall).

Siemens recommends operators check whether appropriate resilient protection measures are in place as the risk of cyber incidents impacting the grid’s reliability can thus be minimized by virtue of the grid design.

Siemens strongly recommends applying the provided security updates using the corresponding tooling and documented procedures made available with the product. If supported by the product, an automated means to apply the security updates across multiple product instances may be used. Siemens strongly recommends prior validation of any security update before being applied, and supervision by trained staff of the update process in the target environment.

As a general security measure, Siemens strongly recommends protecting network access with appropriate mechanisms (e.g.
firewalls, segmentation, VPN). It is advised to configure the environment according to Siemens’ operational guidelines in order to run the devices in a protected IT environment.

Recommended security guidelines to Secure Substations can be found at https://www.siemens.com/gridsecurity

For more information on these vulnerabilities and more detailed mitigation instructions, please see Siemens security advisory SSA-418979 at the following location:

http://www.siemens.com/cert/advisories

Plugin Details

Severity: High

ID: 500352

Version: 1.7

Type: remote

Family: Tenable.ot

Published: 2/7/2022

Updated: 9/4/2024

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS Score Source: CVE-2019-13942

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:siemens:en100_ethernet_module_with_firmware_variant_profinet_io, cpe:/o:siemens:en100_ethernet_module_with_firmware_variant_iec104, cpe:/o:siemens:en100_ethernet_module_with_firmware_variant_dnp3_tcp, cpe:/o:siemens:en100_ethernet_module_with_firmware_variant_modbus_tcp, cpe:/o:siemens:en100_ethernet_module_with_firmware_variant_iec_61850

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 12/12/2019

Vulnerability Publication Date: 12/12/2019

Reference Information

CVE: CVE-2019-13942

CWE: 119

ICSA: 19-344-07

Detections

Analytics