CVE-2020-8867

mediumpriority · track · 31EPSS 0.026 · 86 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

2.64% (86th) EPSS

CVSS 5 · medium

Is it mine?

3 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · nvd · osv

EPSS · scored 2026-10-27

This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of OPC Foundation UA .NET Standard 1.04.358.30. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of sessions. The issue results from the lack of proper locking when performing operations on an object. An attacker can leverage this vulnerability to create a denial-of-service condition against the application. Was ZDI-CAN-10295.

cvss

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5–7.5

v2.05mediumAV:N/AC:L/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 10 · impact 2.9

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.05.3mediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Lsecondary · ENISA EU

v3.05.3mediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Lsecondary · zdi-disclosures@trendmicro.comexploitability 3.9 · impact 1.4

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · OSV

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-613USprimaryCWE-367USCWE-367USCWE-613US

affected products (3)

Products and version ranges known to be affected.

OPC Foundation UA .NET Standard≤ 1.04.358.30enisa_euvdEU
opcfoundation unified architecture .net-standard≤ 1.04.358.30nvdUScpe:2.3:a:opcfoundation:unified_architecture_.net-standard:*:*:*:*:*:*:*:*
NuGet OPCFoundation.NetStandard.Opc.Ua< 1.4.359.31osvUSpkg:nuget/OPCFoundation.NetStandard.Opc.Ua

advisories (1)

Vendor and ecosystem advisories describing this.

GHSA-9q94-v7ch-mxqwInsufficient Session Expiration and TOCTOU Race Condition in OPC FOundation UA .Net Standard2021-08-02ghsa · osvUS
This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of OPC Foundation UA .NET Standard 1.04.358.30. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of sessions. The issue results from the lack of proper locking when performing operations on an object. An attacker can leverage this vulnerability to create a denial-of-service condition against the application. Was ZDI-CAN-10295.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd osv NVD CVE.org MITRE

published 2020-04-22modified 2026-06-17

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+728 more

references (8)

External citations — patches, advisories, analysis.

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