CVE-2020-11899

Treck TCP/IP stack Out-of-Bounds Read Vulnerability

The Treck TCP/IP stack before 6.0.1.66 has an IPv6 Out-of-bounds Read.

CVSS 5.4 KEVPatch available

This record: live connection— last retrieved: 7 November 2026 at 02:35.

Vendor

Pepperl+Fuchs

Product

VDM100

up to version <=2.00

Published

17 June 2020

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

The Treck TCP/IP stack before 6.0.1.66 has an IPv6 Out-of-bounds Read.

CVSS 3.1 — vector details

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

Attack vector

NETWORK

Privileges required

NONE

User interaction

NONE

Confidentiality

None

Integrity

Limited

Availability

Limited

EPSS — Exploit Prediction Scoring System

Probability of exploitation within 30 days

18.4%

Percentile

97e

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

Patch information

An external protective measure is required. - Minimize network exposure for affected products and ensure that they are not accessible via the Internet. - Isolate affected products from the corporate network. - If remote access is required, use secure methods such as virtual private networks (VPNs).

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

59/ 100

Based on CVSS 5.4, EPSS 18.4%, industrial relevance 50/100; raised due to confirmed active exploitation (KEV).

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

Limited impact on availability; the risk lies mainly with confidentiality or integrity of process data.

No strong energy-sector-specific signals recognised; general OT/ICS relevance.

Additional mitigations

•Apply updates per vendor instructions.

Recommended defensive measures

•Apply the latest firmware or software update and validate its integrity.
•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

50/ 100

• Mentioned in an official CISA ICS advisory, which confirms direct relevance to industrial control systems.
• Included in the CISA KEV catalogue: confirmed evidence of actual exploitation.

Classification is provisional; manual verification by an OT security analyst is recommended.

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

IEC 62443 mapping

IEC 62443-4-1FR3 · Systeemintegriteit

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

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