Siemens EN100 Ethernet Module Improper Restriction of Operations Within the Bounds of a Memory Buffer (CVE-2022-30938)

high Tenable OT Security Plugin ID 500692

Synopsis

The remote OT asset is affected by a vulnerability.

Description

A vulnerability has been identified in EN100 Ethernet module DNP3 IP variant (All versions), EN100 Ethernet module IEC 104 variant (All versions), EN100 Ethernet module IEC 61850 variant (All versions < V4.40), EN100 Ethernet module Modbus TCP variant (All versions), EN100 Ethernet module PROFINET IO variant (All versions). Affected applications contains a memory corruption vulnerability while parsing specially crafted HTTP packets to /txtrace endpoint manupulating a specific argument. This could allow an attacker to crash the affected application leading to a denial of service condition

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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 an update for the EN100 Ethernet module IEC 61850 variant and recommends updating to the latest version. Siemens recommends specific countermeasures for products where updates are either not implemented or not yet available.

- EN100 Ethernet module IEC 61850 variant: Update to v4.40 or later version

Siemens recommends implementing the following specific workarounds and mitigations that customers can apply to reduce the risk:

- Disable web service within the device configuration if it is not used
- Block access to port 80/TCP and 443/TCP e.g., with an external firewall
- Apply secure substation concept and defense-in-depth or contact customer care to find specific solutions

Operators of critical power systems worldwide are usually required by regulations to build resilience into the power grid by applying multi-level redundant secondary protection schemes. Siemens recommends that operators check whether appropriate resilient protection measures are in place. 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 application. Trained supervisors should oversee the during the update process as this will ensure that thorough updates are implemented in the target environment.

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

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

For more information on these vulnerabilities and associated software updates, please see Siemens security advisory SSA-865333

See Also

https://cert-portal.siemens.com/productcert/pdf/ssa-865333.pdf

https://www.cisa.gov/news-events/ics-advisories/icsa-22-195-16

Plugin Details

Severity: High

ID: 500692

Version: 1.6

Type: remote

Family: Tenable.ot

Published: 8/2/2022

Updated: 3/4/2024

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-2022-30938

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_dnp3_ip_firmware, cpe:/o:siemens:en100_ethernet_module_iec_104_firmware, cpe:/o:siemens:en100_ethernet_module_iec_61850_firmware, cpe:/o:siemens:en100_ethernet_module_modbus_tcp_firmware, cpe:/o:siemens:en100_ethernet_module_profinet_io_firmware:-

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 7/12/2022

Vulnerability Publication Date: 7/12/2022

Reference Information

CVE: CVE-2022-30938

CWE: 119