CVE-2021-20999

Weidmüller IOT-GW30 — vulnerability CVE-2021-20999

In Weidmüller u-controls and IoT-Gateways in versions up to 1.12.1 a network port intended only for device-internal usage is accidentally accessible via external network interfaces. By exploiting this vulnerability the device may be manipulated or the operation may be stopped.

CVSS 9.4No patch available

This record: live connection— last retrieved: 7 November 2026 at 02:05.

Vendor

Weidmüller

Products

IOT-GW30, IOT-GW30-4G-EU, UC20-WL2000-AC, UC20-WL2000-IOT

up to version 1.3.0<=1.9.0

Published

13 May 2021

Last modified

17 June 2026

Original source information

Taken directly from NVD, CISA or the vendor — sometimes in English, unchanged from the source.

Technical description

CVSS 3.1 — vector details

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H

Attack vector

NETWORK

Privileges required

NONE

User interaction

NONE

Confidentiality

Limited

Integrity

High

Availability

High

EPSS — Exploit Prediction Scoring System

Probability of exploitation within 30 days

0.9%

Percentile

61e

Source: FIRST.org, updated on 6 November 2026.

Patch information

Restrict access to the network th device is connected to Do not directly connect the device to the internet

IACS Radar assessment

Our own interpretation and context for the source data above.

IACS Radar assessment

Our own interpretation and context for this vulnerability — not an official source.

IACS Radar priority score

54/ 100

Based on CVSS 9.4, EPSS 0.9%, industrial relevance 60/100.

Combines CVSS, EPSS, KEV status, industrial relevance and exposure relevance — a complement to, not a replacement for, the individual scores below and above.

Conditions for exploitation

•Network access to the affected device or segment is required.
•No valid credentials are needed.
•No user interaction required.

Operational impact & energy relevance

Possible loss of visibility of or control over the process upon successful exploitation.

Assessed as relevant to the energy sector based on: Vermeld in een officiële CISA ICS Advisory, wat directe relevantie voor industriële besturingssystemen bevestigt. Productbeschrijving komt overeen met de categorie "protocol-gateway", een typisch OT/ICS-componenttype.

Recommended defensive measures

•Implement network segmentation in line with zones and conduits (IEC 62443-3-2).
•Restrict network access to the affected device to a dedicated OT management segment.
•Implement network segmentation in line with zones and conduits (IEC 62443-3-2).
•Monitor for abnormal protocol traffic using an OT-aware detection system.

Industrial relevance score

60/ 100

• Mentioned in an official CISA ICS advisory, which confirms direct relevance to industrial control systems.
• Product description matches the category "protocol-gateway", a typical OT/ICS component type.

Automatically classified as industrially relevant based on CISA/NVD signals (see reasons).

Classified by IACS Radar-analysepijplijn (geautomatiseerd) on 7 November 2026.

IEC 62443 mapping

IEC 62443-3-2FR5 · Beperking van datastromen

Automatic IACS Radar assessment based on the reported CWE weakness classification; not an official certification statement.

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