No exploitation reportedFix available

CVE-2018-4838

Q: Is CVE-2018-4838 actively exploited?

Active exploitation of CVE-2018-4838 has not been confirmed. Its EPSS score was 1.4% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2018-4838?

CVE-2018-4838 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

No exploitation reported by the sources we read.

Published2018-03-08
WeaknessCWE-306

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A vulnerability has been identified in EN100 Ethernet module IEC 61850 variant (All versions < V4.30), EN100 Ethernet module DNP3 variant (All versions < V1.04), EN100 Ethernet module PROFINET IO variant (All versions), EN100 Ethernet module Modbus TCP variant (All versions), EN100 Ethernet module IEC 104 variant (All versions < V1.22). The web interface (TCP/80) of affected devices allows an unauthenticated user to upgrade or downgrade the firmware of the device, including to older versions with known vulnerabilities.

Timeline

dates in UTC

2018-03-0817:29CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2018-4838?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2018-4838?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Siemens en100 ethernet module dnp3 firmwareversion to verify

Branch	Affected	Fixed in	Source
—	all versions	no fix published	NVD

Siemens en100 ethernet module iec 104 firmwareversion to verify

Branch	Affected	Fixed in	Source
—	all versions	no fix published	NVD

Siemens en100 ethernet module iec 61850 firmwareversion to verify

Branch	Affected	Fixed in	Source
4.30	< 4.30	4.30	NVD

2 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

ICSA-18-067-02 CISA5 known affected
ICSA-18-067-02_Siemens SIPROTEC 4, SIPROTEC Compact, and Reyrolle Devices using the EN100 Ethernet Communication Module Extension (Update B)
EN100 Ethernet module DNP3 variant: All versions prior to v1.04 · EN100 Ethernet module IEC 61850 variant: All versions prior to V4.30 · EN100 Ethernet module Modbus TCP variant: All versions · +2 more

Full record on NVD

Fix

Mitigation from the vendor CISA ICSA-18-067-02 · 5 productsFor all other affected products, Siemens has identified the following specific workarounds and mitigations that users can apply to reduce the risk. As a general security measure Siemens strongly recommends to protect network access with appropriate mechanisms (e.g., firewalls, segmentation, VPN). I…
Mitigation from the vendor CISA ICSA-18-067-02 · 5 productsEN100 Ethernet module DNP3 variant (All versions prior to v1.04): Update to v1.04 and configure maintenance password, which can be located here: https://support.industry.siemens.com/cs/us/en/ view/109745821
Mitigation from the vendor CISA ICSA-18-067-02 · 5 productsEN100 Ethernet module IEC 61850 variant (All versions prior to v4.30): Update to v4.30, which can be located here: https://support.industry.siemens.com/cs/us/en/view/109745821
Mitigation from the vendor CISA ICSA-18-067-02 · 5 productsEN100 Ethernet module IEC 104 variant: Update to v1.22, which can be located here: https://support.industry.siemens.com/cs/document/109745821

Advisories and patches

cert-portal.siemens.comPatch · Vendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.07.5read 2026-10-23
NVDCVSS 2.05read 2026-10-23
NVDweakness (CWE)CWE-306read 2026-10-23
FIRST EPSSEPSS score1.4 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Published: 2018-03-08
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2018-4838?

Is CVE-2018-4838 actively exploited?

Active exploitation of CVE-2018-4838 has not been confirmed. Its EPSS score was 1.4% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2018-4838?

CVE-2018-4838 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

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