CVE-2020-27299Network attack vector

Data disclosure or crash via heap over-read

Published Jan 26, 2021 · Updated Aug 4, 2024

Out-of-bounds read in Honeywell Technologies Matrikon OPC UA Tunneller before 6.3.0.8233 allows remote attackers to disclose data or crash it. Published technical material identifies a heap over-read but does not identify the affected parser, function, or message field. No authentication or user interaction is required; exploitation exposes process data or terminates the service without modifying data.

CVSS severity9.1
Critical
EPSS probability1.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Honeywell Technologies Matrikon OPC UA Tunneller before 6.3.0.8233 allows remote attackers to disclose data or crash it. Published technical material identifies a heap over-read but does not identify the affected parser, function, or message field. No authentication or user interaction is required; exploitation exposes process data or terminates the service without modifying data.

The record

CVE
CVE-2020-27299
Published
Jan 26, 2021
Updated
Aug 4, 2024
Vendor
Honeywell Technologies
Product
Matrikon OPC UA Tunneller
Classifications
CWE-125, T0866
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 26, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=All versions prior to 6.3.0.8233

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Honeywell Technologies · Matrikon OPC UA Tunnellerversion=All versions prior to 6.3.0.8233

Published CVSS scores

9.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
8.2JVNCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
6.4NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T0866Exploitation of Remote Services

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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