CVE-2021-37199

highpriority · track · 30EPSS 0.011 · 64 %ileDEEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

1.06% (64th) EPSS

CVSS 7.8 · high

Is it mine?

10 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · cisa_csaf_ot · nvd

EPSS · scored 2026-10-27

A vulnerability has been identified in SINUMERIK 808D (All versions), SINUMERIK 828D (All versions < V4.95). Affected devices don't process correctly certain special crafted packets sent to port 102/tcp, which could allow an attacker to cause a denial-of-service in the device.

remediations

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

A vendor fix is available.

FixedSINUMERIK 828Dsiemens_psirt
Update to V4.95 or later version
FixedSINUMERIK 828Dcisa_csaf_ot
Update to V4.95 or later version
MitigationSINUMERIK 808Dsiemens_psirt
Restrict access to port 102/tcp to trusted systems e.g. with an external firewall
MitigationSINUMERIK 828Dsiemens_psirt
Restrict access to port 102/tcp to trusted systems e.g. with an external firewall
MitigationSINUMERIK 808Dcisa_csaf_ot
Restrict access to port 102/tcp to trusted systems e.g. with an external firewall
MitigationSINUMERIK 828Dcisa_csaf_ot
Restrict access to port 102/tcp to trusted systems e.g. with an external firewall
WorkaroundSINUMERIK 808Dsiemens_psirt
Apply general workarounds.
WorkaroundSINUMERIK 828Dsiemens_psirt
Apply general workarounds.
WorkaroundSINUMERIK 808Dcisa_csaf_ot
Apply general workarounds.
WorkaroundSINUMERIK 828Dcisa_csaf_ot
Apply general workarounds.
No fix availableSINUMERIK 808Dsiemens_psirt
Currently no remediation is available
No fix availableSINUMERIK 808Dcisa_csaf_ot
Currently no remediation is available

cvss

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

7.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.8

v2.07.8highAV:N/AC:L/Au:N/C:N/I:N/A:Cprimary · NVD / NIST USexploitability 10 · impact 6.9

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

v3.17.5highCVSS: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-787USprimaryCWE-122USCWE-122USCWE-122US

affected products (10)

Products and version ranges known to be affected.

SINUMERIK 808Dall versionscisa_csaf_otUS
SINUMERIK 828Dall versionscisa_csaf_otUS
Siemens SINUMERIK 808D≤ vers:all/*cisa_csaf_otUS
Siemens SINUMERIK 828D< V4.95cisa_csaf_otUS
Siemens SINUMERIK 808D≤ All versionsenisa_euvdEU
Siemens SINUMERIK 828DAll versions → V4.95enisa_euvdEU
siemens sinumerik 808d firmwareall versionsnvdUScpe:2.3:o:siemens:sinumerik_808d_firmware:*:*:*:*:*:*:*:*
siemens sinumerik 828d firmware< 4.95nvdUScpe:2.3:o:siemens:sinumerik_828d_firmware:*:*:*:*:*:*:*:*
Siemens SINUMERIK 808D≤ vers:all/*siemens_psirtDE
Siemens SINUMERIK 828D< V4.95siemens_psirtDE

advisories (2)

Vendor and ecosystem advisories describing this.

SSA-178380SSA-178380: Denial-of-Service Vulnerability in SINUMERIK Controllers2021-10-12csaf · siemens_psirtDE
A Denial-of-Service vulnerability found in SINUMERIK Controllers could allow an unauthenticated attacker with network access to the affected devices to cause system failure with total loss of availability. Siemens has released an update for the SINUMERIK 828D and recommends to update to the latest version. Siemens recommends specific countermeasures for products where updates are not, or not yet available.
ICSA-21-287-04Siemens SINUMERIK2021-10-12icsa · cisa_csaf_otUS
A Denial-of-Service vulnerability found in SINUMERIK Controllers could allow an unauthenticated attacker with network access to the affected devices to cause system failure with total loss of availability. Siemens has released an update for the SINUMERIK 828D and recommends to update to the latest version. Siemens recommends specific countermeasures for products where updates are not, or not yet available.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd cisa_csaf_ot nvd siemens_psirt NVD CVE.org MITRE

published 2021-10-12modified 2026-06-17

related (16,129)

Related entries.

ID	severity	EPSS	exploitable	published
CVE-2026-86950US	—OT critical	26.2% (98th)	KEV	2026-09-28
An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 18.7.11 and iPadOS 18.7.11, iOS 26.7.1 and iPadOS 26.7.1, macOS Sequoia 15.8.1,…
CVE-2026-87491US	—OT critical	3.51% (89th)	KEV	2026-09-09
Out of bounds write in V8 in Google Chrome prior to 153.0.8010.36 allowed a remote attacker to execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security…
CVE-2026-53362US	—OT critical	0.71% (53rd)	KEV	2026-07-04
In the Linux kernel, the following vulnerability has been resolved: ipv6: account for fraggap on the paged allocation path In __ip6_append_data(), when the paged-allocation branc…
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-2026-11645US	—OT critical	2.44% (84th)	KEV	2026-06-09
Out of bounds read and write in V8 in Google Chrome prior to 149.0.7827.103 allowed a remote attacker to execute arbitrary code inside a sandbox via a crafted HTML page. (Chromium…

+16124 more

references (7)

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