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Vulnerability details: VCID-eckc-sv2r-uygz
Vulnerability ID VCID-eckc-sv2r-uygz
Aliases CVE-2023-27321
GHSA-vpf7-r2fv-75m9
Summary Uncontrolled Resource Consumption in OPC UA .NET Standard Reference Server This security update resolves a vulnerability in the OPC UA .NET Standard Reference Server that allows remote attackers to send malicious requests that consume all memory available to the server. https://files.opcfoundation.org/SecurityBulletins/OPC%20Foundation%20Security%20Bulletin%20CVE-2023-27321.pdf
Status Published
Exploitability 0.5
Weighted Severity 8.0
Risk 4.0
Affected and Fixed Packages Package Details
Weaknesses (3)
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
CWE-400 Uncontrolled Resource Consumption
System Score Found at
epss 0.01308 https://api.first.org/data/v1/epss?cve=CVE-2023-27321
epss 0.01308 https://api.first.org/data/v1/epss?cve=CVE-2023-27321
epss 0.01308 https://api.first.org/data/v1/epss?cve=CVE-2023-27321
epss 0.01308 https://api.first.org/data/v1/epss?cve=CVE-2023-27321
epss 0.01308 https://api.first.org/data/v1/epss?cve=CVE-2023-27321
epss 0.01308 https://api.first.org/data/v1/epss?cve=CVE-2023-27321
epss 0.01308 https://api.first.org/data/v1/epss?cve=CVE-2023-27321
epss 0.01308 https://api.first.org/data/v1/epss?cve=CVE-2023-27321
epss 0.01308 https://api.first.org/data/v1/epss?cve=CVE-2023-27321
epss 0.01308 https://api.first.org/data/v1/epss?cve=CVE-2023-27321
epss 0.01308 https://api.first.org/data/v1/epss?cve=CVE-2023-27321
epss 0.01308 https://api.first.org/data/v1/epss?cve=CVE-2023-27321
epss 0.01308 https://api.first.org/data/v1/epss?cve=CVE-2023-27321
cvssv3 7.5 https://files.opcfoundation.org/SecurityBulletins/OPC%20Foundation%20Security%20Bulletin%20CVE-2023-27321.pdf
cvssv3.1 7.5 https://files.opcfoundation.org/SecurityBulletins/OPC%20Foundation%20Security%20Bulletin%20CVE-2023-27321.pdf
generic_textual HIGH https://files.opcfoundation.org/SecurityBulletins/OPC%20Foundation%20Security%20Bulletin%20CVE-2023-27321.pdf
ssvc Track https://files.opcfoundation.org/SecurityBulletins/OPC%20Foundation%20Security%20Bulletin%20CVE-2023-27321.pdf
cvssv3.1_qr HIGH https://github.com/advisories/GHSA-vpf7-r2fv-75m9
cvssv3.1 7.5 https://github.com/OPCFoundation/UA-.NETStandard
generic_textual HIGH https://github.com/OPCFoundation/UA-.NETStandard
cvssv3.1 7.5 https://github.com/OPCFoundation/UA-.NETStandard/security/advisories/GHSA-vpf7-r2fv-75m9
cvssv3.1_qr HIGH https://github.com/OPCFoundation/UA-.NETStandard/security/advisories/GHSA-vpf7-r2fv-75m9
generic_textual HIGH https://github.com/OPCFoundation/UA-.NETStandard/security/advisories/GHSA-vpf7-r2fv-75m9
cvssv3.1 7.5 https://nvd.nist.gov/vuln/detail/CVE-2023-27321
generic_textual HIGH https://nvd.nist.gov/vuln/detail/CVE-2023-27321
cvssv3.1 7.5 https://www.zerodayinitiative.com/advisories/ZDI-23-548
generic_textual HIGH https://www.zerodayinitiative.com/advisories/ZDI-23-548
cvssv3 7.5 https://www.zerodayinitiative.com/advisories/ZDI-23-548/
ssvc Track https://www.zerodayinitiative.com/advisories/ZDI-23-548/
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2023-27321
https://files.opcfoundation.org/SecurityBulletins/OPC%20Foundation%20Security%20Bulletin%20CVE-2023-27321.pdf
https://github.com/OPCFoundation/UA-.NETStandard
https://nvd.nist.gov/vuln/detail/CVE-2023-27321
https://www.zerodayinitiative.com/advisories/ZDI-23-548
GHSA-vpf7-r2fv-75m9 https://github.com/advisories/GHSA-vpf7-r2fv-75m9
GHSA-vpf7-r2fv-75m9 https://github.com/OPCFoundation/UA-.NETStandard/security/advisories/GHSA-vpf7-r2fv-75m9
ZDI-23-548 https://www.zerodayinitiative.com/advisories/ZDI-23-548/
No exploits are available.
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://files.opcfoundation.org/SecurityBulletins/OPC%20Foundation%20Security%20Bulletin%20CVE-2023-27321.pdf
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://files.opcfoundation.org/SecurityBulletins/OPC%20Foundation%20Security%20Bulletin%20CVE-2023-27321.pdf
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: SSVCv2/E:N/A:Y/T:P/P:M/B:A/M:M/D:T/2024-05-08T15:27:13Z/ Found at https://files.opcfoundation.org/SecurityBulletins/OPC%20Foundation%20Security%20Bulletin%20CVE-2023-27321.pdf
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/OPCFoundation/UA-.NETStandard
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/OPCFoundation/UA-.NETStandard/security/advisories/GHSA-vpf7-r2fv-75m9
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2023-27321
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://www.zerodayinitiative.com/advisories/ZDI-23-548
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://www.zerodayinitiative.com/advisories/ZDI-23-548/
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: SSVCv2/E:N/A:Y/T:P/P:M/B:A/M:M/D:T/2024-05-08T15:27:13Z/ Found at https://www.zerodayinitiative.com/advisories/ZDI-23-548/
Exploit Prediction Scoring System (EPSS)
Percentile 0.79739
EPSS Score 0.01308
Published At April 2, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-04-01T12:51:15.178065+00:00 GitLab Importer Import https://gitlab.com/gitlab-org/advisories-community/-/blob/main/nuget/OPCFoundation.NetStandard.Opc.Ua.Server/CVE-2023-27321.yml 38.0.0