CVE-2021-40142

mediumpriority · track · 31EPSS 0.026 · 85 %ileDEEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

2.56% (85th) EPSS

CVSS 5 · medium

Is it mine?

52 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · cisa_csaf_ot

EPSS · scored 2026-10-27

In OPC Foundation Local Discovery Server (LDS) before 1.04.402.463, remote attackers can cause a denial of service (DoS) by sending carefully crafted messages that lead to Access of a Memory Location After the End of a Buffer.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedSIMATIC NET PC Software V14siemens_psirt
Update to V14 SP1 Update 14 or later version
https://support.industry.siemens.com/cs/ww/en/view/109807351/
FixedSIMATIC NET PC Software V16siemens_psirt
Update to V16 Update 6 or later version
FixedSIMATIC NET PC Software V17siemens_psirt
Update to V17 SP1 or later version
FixedSIMATIC Process Historian OPC UA Serversiemens_psirt
For PCS 7: Update to PCS 7 V9.1 SP1 ( https://support.industry.siemens.com/cs/ww/en/view/109805073/)
FixedSIMATIC WinCCsiemens_psirt
Update to V8.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109816599/
FixedSIMATIC WinCC Runtime Professionalsiemens_psirt
Update to V18 or later version
https://support.industry.siemens.com/cs/ww/en/view/109813587/
FixedSIMATIC WinCC Unified PC Runtime V18siemens_psirt
Update to V18 Update 1 or later version
https://support.industry.siemens.com/cs/ww/en/view/109807123/
FixedTeleControl Server Basic V3siemens_psirt
Update to V3.1.1 or later version
https://support.industry.siemens.com/cs/ww/en/view/109812231/
FixedSIMATIC NET PC Software V14cisa_csaf_ot
Update to V14 SP1 Update 14 or later version
https://support.industry.siemens.com/cs/ww/en/view/109807351/
FixedSIMATIC NET PC Software V16cisa_csaf_ot
Update to V16 Update 6 or later version
FixedSIMATIC NET PC Software V17cisa_csaf_ot
Update to V17 SP1 or later version
FixedSIMATIC Process Historian OPC UA Servercisa_csaf_ot
For PCS 7: Update to PCS 7 V9.1 SP1 ( https://support.industry.siemens.com/cs/ww/en/view/109805073/)
FixedSIMATIC WinCCcisa_csaf_ot
Update to V8.0 or later version
https://support.industry.siemens.com/cs/ww/en/view/109816599/
FixedSIMATIC WinCC Runtime Professionalcisa_csaf_ot
Update to V18 or later version
https://support.industry.siemens.com/cs/ww/en/view/109813587/
FixedSIMATIC WinCC Unified PC Runtime V18cisa_csaf_ot
Update to V18 Update 1 or later version
https://support.industry.siemens.com/cs/ww/en/view/109807123/
FixedTeleControl Server Basic V3cisa_csaf_ot
Update to V3.1.1 or later version
https://support.industry.siemens.com/cs/ww/en/view/109812231/
MitigationOpenPCS 7 V9.1siemens_psirt
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
MitigationSIMATIC NET PC Software V14siemens_psirt
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
MitigationSIMATIC NET PC Software V15siemens_psirt
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
MitigationSIMATIC NET PC Software V16siemens_psirt
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
MitigationSIMATIC NET PC Software V17siemens_psirt
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
MitigationSIMATIC Process Historian OPC UA Serversiemens_psirt
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
MitigationSIMATIC WinCCsiemens_psirt
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
MitigationSIMATIC WinCC Runtime Professionalsiemens_psirt
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
MitigationSIMATIC WinCC Unified PC Runtime V18siemens_psirt
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
MitigationTeleControl Server Basic V3siemens_psirt
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
MitigationOpenPCS 7 V9.1cisa_csaf_ot
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
MitigationSIMATIC NET PC Software V14cisa_csaf_ot
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
MitigationSIMATIC NET PC Software V15cisa_csaf_ot
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
MitigationSIMATIC NET PC Software V16cisa_csaf_ot
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
MitigationSIMATIC NET PC Software V17cisa_csaf_ot
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
MitigationSIMATIC Process Historian OPC UA Servercisa_csaf_ot
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
MitigationSIMATIC WinCCcisa_csaf_ot
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
MitigationSIMATIC WinCC Runtime Professionalcisa_csaf_ot
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
MitigationSIMATIC WinCC Unified PC Runtime V18cisa_csaf_ot
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
MitigationTeleControl Server Basic V3cisa_csaf_ot
Deactivate the OPC LDS Service if supported by the product use case. The LDS service is not activated in the default configuration
No fix plannedOpenPCS 7 V9.1siemens_psirt
Currently no fix is planned
No fix plannedSIMATIC NET PC Software V15siemens_psirt
Currently no fix is planned
No fix plannedOpenPCS 7 V9.1cisa_csaf_ot
Currently no fix is planned
No fix plannedSIMATIC NET PC Software V15cisa_csaf_ot
Currently no fix is planned

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

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:Csecondary · CISA US

v3.17.5highAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU

v3.17.5highCVSS:3.1/AC:L/AV:N/A:H/C:N/I:N/PR:N/S:U/UI:Nsecondary · ENISA EU

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · cve@mitre.org USexploitability 3.9 · impact 3.6

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:Csecondary · Siemens ProductCERT DE

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-119USprimaryCWE-119USCWE-119USCWE-119USCWE-120USCWE-788US

affected products (52)

Products and version ranges known to be affected.

OpenPCS 7 V9.1all versionscisa_csaf_otUS
SIMATIC NET PC Software V14all versionscisa_csaf_otUS
SIMATIC NET PC Software V15all versionscisa_csaf_otUS
SIMATIC NET PC Software V16all versionscisa_csaf_otUS
SIMATIC NET PC Software V17all versionscisa_csaf_otUS
SIMATIC Process Historian OPC UA Serverall versionscisa_csaf_otUS
SIMATIC WinCCall versionscisa_csaf_otUS
SIMATIC WinCC Runtime Professionalall versionscisa_csaf_otUS
SIMATIC WinCC Unified PC Runtime V18all versionscisa_csaf_otUS
TeleControl Server Basic V3all versionscisa_csaf_otUS
Siemens OpenPCS 7 V9.1≤ vers:all/*cisa_csaf_otUS
Siemens SIMATIC NET PC Software V14< V14_SP1_Update_14cisa_csaf_otUS
Siemens SIMATIC NET PC Software V15≤ vers:all/*cisa_csaf_otUS
Siemens SIMATIC NET PC Software V16< V16_Update_6cisa_csaf_otUS
Siemens SIMATIC NET PC Software V17< V17_SP1cisa_csaf_otUS
Siemens SIMATIC Process Historian OPC UA Server< V2020_SP1cisa_csaf_otUS
Siemens SIMATIC WinCC< V8.0cisa_csaf_otUS
Siemens SIMATIC WinCC Runtime Professional< V18cisa_csaf_otUS
Siemens SIMATIC WinCC Unified PC Runtime V18< V18_Update_1cisa_csaf_otUS
Siemens TeleControl Server Basic V3< V3.1.1cisa_csaf_otUS

showing 20 of 52

advisories (2)

Vendor and ecosystem advisories describing this.

SSA-321292SSA-321292: Denial of Service in the OPC Foundation Local Discovery Server (LDS) in Industrial Products2022-05-10csaf · siemens_psirtDE
A vulnerability has been identified in the OPC Foundation Local Discovery Server (LDS) [0] of several industrial products. The vulnerability could cause a denial of service condition on the service or the device. Siemens has released new versions for several affected products and recommends to update to the latest versions. Siemens recommends specific countermeasures for products where fixes are not, or not yet available. [0] https://files.opcfoundation.org/SecurityBulletins/OPC%20Foundation%20Security%20Bulletin%20CVE-2021-40142.pdf
ICSA-22-132-12Siemens Industrial Products2022-05-10icsa · cisa_csaf_otUS
A vulnerability has been identified in the OPC Foundation Local Discovery Server (LDS) [0] of several industrial products. The vulnerability could cause a denial of service condition on the service or the device. Siemens has released new versions for several affected products and recommends to update to the latest versions. Siemens recommends specific countermeasures for products where fixes are not, or not yet available. [0] https://files.opcfoundation.org/SecurityBulletins/OPC%20Foundation%20Security%20Bulletin%20CVE-2021-40142.pdf

also known as (5)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cisa_csaf_ot siemens_psirt NVD CVE.org MITRE

published 2021-08-27modified 2026-06-17

related (21,028)

Related entries.

ID	severity	EPSS	exploitable	published
CVE-2026-88779US	high7.5OT critical	11.4% (96th)	KEV	2026-10-04
Vulnerability in NetScaler ADC and NetScaler Gateway. This issue affects ADC: before 14.1-73.41, before 13.1-64.28, before 14.1-73.41 FIPS, and before 13.1-37.282; Gateway: before…
CVE-2026-88772US	high8.1OT critical	78.2% (100th)	KEV	2026-09-27
Vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway. This issue affects ADC: before 14.1-73.37, before 13.1-64.23, before 14.1-73.37 FIPS, and before 13.1.37.279 FI…
CVE-2026-8452US	critical9.8OT critical	1.01% (63rd)	KEV	2026-06-30
Memory overflow vulnerability NetScaler ADC and NetScaler Gateway leading to unpredictable or erroneous behavior and Denial of Service if the appliance is configured as a Gateway (…
CVE-2026-53266US	—OT critical	0.93% (61st)	KEV	2026-06-25
In the Linux kernel, the following vulnerability has been resolved: netfilter: bridge: make ebt_snat ARP rewrite writable The ebtables SNAT target keeps the Ethernet source addre…
CVE-2026-3910US	high8.8OT critical	2.69% (86th)	KEV	2026-03-13
Inappropriate implementation in V8 in Google Chrome prior to 146.0.7680.75 allowed a remote attacker to execute arbitrary code inside a sandbox via a crafted HTML page. (Chromium s…

+21023 more

references (13)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan