BlackTreeCVE Intelligence
← Back to the CVE catalogue
Full vulnerability report · 2022
CVE-2021-44693High confidence

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

Siemens · SIMATIC Drive Controller CPU 1504D TF

Official source article: Siemens SSA-382653 ↗. Check the applicable product and release in the original source.

4.9MediumCVSS 3.1
Recommended action
Patch only the product branches with a verified fix

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 109 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • EPSS is 0.74% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Siemens SIMATIC Drive Controller CPU 1504D TF and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: As exposure requiresRemediation target: Within 365 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Cross-source reconciliation

Remediation availability differs by product scope

Verified remediation exists for at least one product or source, but 109 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
SSA-382653 · CSAF 2.0 · revision 6 · interimSiemens ProductCERTSSA-382653: Multiple Denial of Service Vulnerabilities in Industrial Products
109 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • SIMATIC Drive Controller CPU 1504D TF (6ES7615-4DF10-0AB0)
  • SIMATIC Drive Controller CPU 1507D TF (6ES7615-7DF10-0AB0)
  • SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants)
  • SIMATIC S7-1200 CPU family (incl. SIPLUS variants)
  • SIMATIC S7-1500 CPU 1510SP F-1 PN (6ES7510-1SJ01-0AB0)
  • SIMATIC S7-1500 CPU 1510SP-1 PN (6ES7510-1DJ01-0AB0)
  • SIMATIC S7-1500 CPU 1511-1 PN (6ES7511-1AK01-0AB0)
  • SIMATIC S7-1500 CPU 1511-1 PN (6ES7511-1AK02-0AB0)
  • SIMATIC S7-1500 CPU 1511C-1 PN (6ES7511-1CK00-0AB0)
  • SIMATIC S7-1500 CPU 1511C-1 PN (6ES7511-1CK01-0AB0)
  • SIMATIC S7-1500 CPU 1511F-1 PN (6ES7511-1FK01-0AB0)
  • SIMATIC S7-1500 CPU 1511F-1 PN (6ES7511-1FK02-0AB0)
Summary
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.
Remediation
Update to V2.3.6 or later version
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2021-31509

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionPatch only the product branches with a verified fix

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 109 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
01

What, why and how

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.

What

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.

Why

The product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may disrupt the affected service.

What

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.

Why

The product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may disrupt the affected service.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Validation of Specified Quantity in Input → disrupt the affected service
Attack surface
Network
Privileges required
High: elevated access is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-1284 ↗

CWE-1284: Improper Validation of Specified Quantity in Input. The product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRHighPrivileges required: The attacker needs elevated or administrative privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkDenial of serviceCWE-1284
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2022-2297Siemens SIMATIC S7: Mehrere Schwachstellen ermöglichen Denial of Service

Ein Angreifer kann mehrere Schwachstellen in Siemens SIMATIC S7 ausnutzen, um einen Denial of Service Angriff durchzuführen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20221214Security Bulletin 14 Dec 2022

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 14 Dec 2022, published on 14 December 2022. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2022-AVI-1094Multiples vulnérabilités dans les produits Siemens

g/CVERecord?id=CVE-2019-13924 Référence CVE CVE-2019-1552 https://www.cve.org/CVERecord?id=CVE-2019-1552 Référence CVE CVE-2019-16905 https://www.cve.org/CVERecord?id=CVE-2019-16905 Référence CVE CVE-2019-6109 https://www.cve.org/CVERecord?id=CVE-2019-6109 Référence CVE CVE-2019-6110 https://www.cve.org/CVERecord?id=CVE-2019-6110 Référence CVE CVE-2019-6111 https://www.cve.org/CVERecord?id=CVE-2019-6111 Référence CVE CVE-2020-28388 https://www.cve.org/CVERecord?id=CVE-2020-28388 Référence CVE CVE-2020-7580 https://www.cve.org/CVERecord?id=CVE-2020-7580 Référence CVE CVE-2021-40365 https://www.cve.org/CVERecord?id=CVE-2021-40365 Référence CVE CVE-2021-44693 https://www.cve.org/CVERecord?id=CVE-2021-44693 Référence CVE CVE-2021-44694 https://www.cve.org/CVERecord?id=CVE-2021-44694 Référence CVE CVE-2021-44695 https://www.cve.org/CVERecord?id=CVE-2021-44695 Référence CVE CVE-2022-30065 https://www.cve.org/CVERecord?id=CVE-2022-30065 Référence CVE CVE-2022-3159 https://www.cve.org/CVERecord?id=CVE-2022-3159 Référence CVE CVE-2022-3160 https://www.cve.org/CVERecord?id=CVE-2022-3160 Référence CVE CVE-2022-3161 https://www.cve.org/CVERecord?id=CVE-2022-3161 Référence CVE CVE-2022-32205 https://www.cve.org/CVERecord?id=CVE-2022-32205 Référence CVE CVE-2022-32206 https://www.cve.org/CVERecord?id=CVE-20

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2021-020593複数のシーメンス製品における入力で指定された数量の不適切な検証に関する脆弱性

simatic s7-plcsim advanced ファームウェア、SIMATIC S7-1200 CPU 1211C ファームウェア、SIMATIC S7-1200 CPU 1212C ファームウェア等複数のシーメンス製品には、入力で指定された数量の不適切な検証に関する脆弱性が存在します。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix availability varies by product
Affected
Fixed
Update to V2.3.6 or later version
Action
Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 13 Dec 2022 · Last source change 21 Apr 2025, 13:45 UTC · CWE-1284 · Improper Validation of Specified Quantity in Input

CVE recordCVE.org · 5.1
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2021-31509
Product sourceVendor CSAF · Siemens ProductCERT
Remediation sourceVendor CSAF · Siemens ProductCERT
CWE sourceCNA
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    All versions < V2.9.7; All versions < V21.9.7; All versions < V4.6.0 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    After
    All versions < V2.9.7; All versions < V21.9.7; All versions < V4.6.0 · Fixed: Update to V2.3.6 or later version
    Siemens ProductCERT ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
Fixed release recorded from official guidance
ENISA EUVD · EUVD-2021-31509↗Siemens ProductCERT security advisory · Siemens SSA-382653↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2021-44693 · cve.blacktree.nl