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CVE-2022-30937NVD status: Modified

EN100 Ethernet module DNP3 IP variant: Out-of-bounds Write

CVE-2022-30937 is a high-severity out-of-bounds write vulnerability in EN100 Ethernet module DNP3 IP variant from Siemens, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected EN100 Ethernet module DNP3 IP variant versions: All versions. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.29% chance of exploitation within 30 days, higher than 71% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update En100 Ethernet Module Iec 61850 Firmware to 4.37 or a later version.
  2. Read the advisory on cert-portal.siemens.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
SiemensEN100 Ethernet module DNP3 IP variantAll versionsNot stated
SiemensEN100 Ethernet module IEC 104 variantAll versionsNot stated
SiemensEN100 Ethernet module IEC 61850 variantAll versions < V4.37Not stated
SiemensEN100 Ethernet module Modbus TCP variantAll versionsNot stated
SiemensEN100 Ethernet module PROFINET IO variantAll versionsNot stated
SiemensEn100 Ethernet Module Dnp3 FirmwareNot specified in the recordNot stated
SiemensEn100 Ethernet Module Iec 104 FirmwareNot specified in the recordNot stated
SiemensEn100 Ethernet Module Iec 61850 Firmwarebefore 4.374.37
SiemensEn100 Ethernet Module Modbus Tcp FirmwareNot specified in the recordNot stated
SiemensEn100 Ethernet Module Profinet Io FirmwareNot specified in the recordNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.5HighNVD
CVSS 2.07.8HighNVD

Official 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 < V4.37), 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. This could allow an attacker to crash the affected application leading to a denial of service condition.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Out-of-bounds Write vulnerabilities (CWE-787)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in EN100 Ethernet module DNP3 IP variant

All EN100 Ethernet module DNP3 IP variant vulnerabilities

Recent Out-of-bounds Write vulnerabilities

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