BlackTreeIndependent security intelligence
← Back to the CVE catalogue
Full vulnerability report · 2021
CVE-2021-31340High confidence

Siemens SIMATIC RF166C — Uncontrolled Resource Consumption

Siemens · SIMATIC RF166C

7.5HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
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-787292 · CSAF 2.0 · revision 3 · finalSiemens ProductCERTSSA-787292: Denial of Service Vulnerability in SIMATIC RFID Readers
25 known affected

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

  • SIMATIC Reader RF610R CMIIT
  • SIMATIC Reader RF610R ETSI
  • SIMATIC Reader RF610R FCC
  • SIMATIC Reader RF615R CMIIT
  • SIMATIC Reader RF615R ETSI
  • SIMATIC Reader RF615R FCC
  • SIMATIC Reader RF650R ARIB
  • SIMATIC Reader RF650R CMIIT
  • SIMATIC Reader RF650R ETSI
  • SIMATIC Reader RF650R FCC
  • SIMATIC Reader RF680R ARIB
  • SIMATIC Reader RF680R CMIIT
Summary
Affected devices do not properly handle large numbers of incoming connections. An attacker may leverage this to cause a Denial-of-Service situation.
Remediation
Update to V4.0 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.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

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-2021-18250

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 actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

A vulnerability has been identified in SIMATIC RF166C (All versions > V1.1 and < V1.3.2), SIMATIC RF185C (All versions > V1.1 and < V1.3.2), SIMATIC RF186C (All versions > V1.1 and < V1.3.2), SIMATIC RF186CI (All versions > V1.1 and < V1.3.2), SIMATIC RF188C (All versions > V1.1 and < V1.3.2), SIMATIC RF188CI (All versions > V1.1 and < V1.3.2), SIMATIC RF360R (All versions < V2.0), SIMATIC Reader RF610R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF610R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF610R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF615R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF615R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF615R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF650R ARIB (All versions > V3.0 < V4.0), SIMATIC Reader RF650R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF650R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF650R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF680R ARIB (All versions > V3.0 < V4.0), SIMATIC Reader RF680R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF680R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF680R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF685R ARIB (All versions > V3.0 < V4.0), SIMATIC Reader RF685R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF685R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF685R FCC (All versions > V3.0 < V4.0). Affected devices do not properly handle large numbers of incoming connections. An attacker may leverage this to cause a Denial-of-Service situation.

What

A vulnerability has been identified in SIMATIC RF166C (All versions > V1.1 and < V1.3.2), SIMATIC RF185C (All versions > V1.1 and < V1.3.2), SIMATIC RF186C (All versions > V1.1 and < V1.3.2), SIMATIC RF186CI (All versions > V1.1 and < V1.3.2), SIMATIC RF188C (All versions > V1.1 and < V1.3.2), SIMATIC RF188CI (All versions > V1.1 and < V1.3.2), SIMATIC RF360R (All versions < V2.0), SIMATIC Reader RF610R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF610R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF610R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF615R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF615R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF615R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF650R ARIB (All versions > V3.0 < V4.0), SIMATIC Reader RF650R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF650R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF650R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF680R ARIB (All versions > V3.0 < V4.0), SIMATIC Reader RF680R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF680R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF680R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF685R ARIB (All versions > V3.0 < V4.0), SIMATIC Reader RF685R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF685R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF685R FCC (All versions > V3.0 < V4.0). Affected devices do not properly handle large numbers of incoming connections. An attacker may leverage this to cause a Denial-of-Service situation.

Why

The product does not properly control the allocation and maintenance of a limited resource.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

A vulnerability has been identified in SIMATIC RF166C (All versions > V1.1 and < V1.3.2), SIMATIC RF185C (All versions > V1.1 and < V1.3.2), SIMATIC RF186C (All versions > V1.1 and < V1.3.2), SIMATIC RF186CI (All versions > V1.1 and < V1.3.2), SIMATIC RF188C (All versions > V1.1 and < V1.3.2), SIMATIC RF188CI (All versions > V1.1 and < V1.3.2), SIMATIC RF360R (All versions < V2.0), SIMATIC Reader RF610R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF610R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF610R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF615R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF615R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF615R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF650R ARIB (All versions > V3.0 < V4.0), SIMATIC Reader RF650R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF650R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF650R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF680R ARIB (All versions > V3.0 < V4.0), SIMATIC Reader RF680R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF680R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF680R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF685R ARIB (All versions > V3.0 < V4.0), SIMATIC Reader RF685R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF685R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF685R FCC (All versions > V3.0 < V4.0). Affected devices do not properly handle large numbers of incoming connections. An attacker may leverage this to cause a Denial-of-Service situation.

Why

The product does not properly control the allocation and maintenance of a limited resource.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

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 → Uncontrolled Resource Consumption → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
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-400 ↗

CWE-400: Uncontrolled Resource Consumption. The product does not properly control the allocation and maintenance of a limited resource.

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:N/UI:N/S:U/C:N/I:N/A:H

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.PRNonePrivileges required: The attacker does not need an account or existing 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.
NetworkUnauthenticatedCWE-400
A

Official authority intelligence

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

CERT-FR · French · CERTFR-2022-AVI-435Multiples vulnérabilités dans les produits Siemens

l Bulletin de sécurité Siemens ssa-732250 du 10 mai 2022 https://cert-portal.siemens.com/productcert/html/ssa-732250.html Bulletin de sécurité Siemens ssa-736385 du 10 mai 2022 https://cert-portal.siemens.com/productcert/html/ssa-736385.html Bulletin de sécurité Siemens ssa-787292 du 10 mai 2022 https://cert-portal.siemens.com/productcert/html/ssa-787292.html Bulletin de sécurité Siemens ssa-789162 du 10 mai 2022 https://cert-portal.siemens.com/productcert/html/ssa-789162.html Référence CVE CVE-2021-22901 https://www.cve.org/CVERecord?id=CVE-2021-22901 Référence CVE CVE-2021-22924 https://www.cve.org/CVERecord?id=CVE-2021-22924 Référence CVE CVE-2021-31340 https://www.cve.org/CVERecord?id=CVE-2021-31340 Référence CVE CVE-2021-40142 https://www.cve.org/CVERecord?id=CVE-2021-40142 Référence CVE CVE-2021-41545 https://www.cve.org/CVERecord?id=CVE-2021-41545 Référence CVE CVE-2021-45117 https://www.cve.org/CVERecord?id=CVE-2021-45117 Référence CVE CVE-2022-24039 https://www.cve.org/CVERecord?id=CVE-2022-24039 Référence CVE CVE-2022-24040 https://www.cve.org/CVERecord?id=CVE-2022-24040 Référence CVE CVE-2022-24041 https://www.cve.org/CVERecord?id=CVE-2022-24041 Référence CVE CVE-2022-24042 https://www.cve.org/CVERecord?id=CVE-2022-24042 Référence CVE CVE-2022-24043 https://www.cve.org/CVERecord?id=

Official advisory
CERT-FR · French · CERTFR-2021-AVI-442Multiples vulnérabilités dans les produits Siemens

rg/CVERecord?id=CVE-2016-7433 Référence CVE CVE-2016-9042 https://www.cve.org/CVERecord?id=CVE-2016-9042 Référence CVE CVE-2017-6458 https://www.cve.org/CVERecord?id=CVE-2017-6458 Référence CVE CVE-2018-0732 https://www.cve.org/CVERecord?id=CVE-2018-0732 Référence CVE CVE-2020-8169 https://www.cve.org/CVERecord?id=CVE-2020-8169 Référence CVE CVE-2020-8286 https://www.cve.org/CVERecord?id=CVE-2020-8286 Référence CVE CVE-2021-27387 https://www.cve.org/CVERecord?id=CVE-2021-27387 Référence CVE CVE-2021-27390 https://www.cve.org/CVERecord?id=CVE-2021-27390 Référence CVE CVE-2021-27399 https://www.cve.org/CVERecord?id=CVE-2021-27399 Référence CVE CVE-2021-31340 https://www.cve.org/CVERecord?id=CVE-2021-31340 Référence CVE CVE-2021-31342 https://www.cve.org/CVERecord?id=CVE-2021-31342 Référence CVE CVE-2021-31343 https://www.cve.org/CVERecord?id=CVE-2021-31343 Référence CVE CVE-2021-33712 https://www.cve.org/CVERecord?id=CVE-2021-33712 Gestion détaillée du document le 08 juin 2021 Version initiale Alertes Avis Bulletins d’actualités Mentions légales Conditions générales À propos Contact cyber.gouv.fr service-public.fr legifrance.gouv.fr info.gouv.fr france.fr info.gouv.fr/risques Premier Ministre / Secrétariat Général de la Défense et de la Sécurité Nationale / Agence nationale de la sécurité des sy

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.
Patch available
Affected
SIMATIC Reader RF610R CMIIT; SIMATIC Reader RF610R ETSI; SIMATIC Reader RF610R FCC; SIMATIC Reader RF615R CMIIT; SIMATIC Reader RF615R ETSI; SIMATIC Reader RF615R FCC; SIMATIC Reader RF650R ARIB; SIMATIC Reader RF650R CMIIT; SIMATIC Reader RF650R ETSI; SIMATIC Reader RF650R FCC; SIMATIC Reader RF680R ARIB; SIMATIC Reader RF680R CMIIT; SIMATIC Reader RF680R ETSI; SIMATIC Reader RF680R FCC; SIMATIC Reader RF685R ARIB; SIMATIC Reader RF685R CMIIT; SIMATIC Reader RF685R ETSI; SIMATIC Reader RF685R FCC; SIMATIC RF166C; SIMATIC RF185C; SIMATIC RF186C; SIMATIC RF186CI; SIMATIC RF188C; SIMATIC RF188CI; SIMATIC RF360R
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.
Action
Update to V4.0 or later version
Workaround
A mitigation or workaround reference is available from the source linked below; validate it against the affected product and version.
04

Evidence and provenance

Published 8 Jun 2021 · Last source change 3 Aug 2024, 22:55 UTC · CWE-400 · Uncontrolled Resource Consumption

CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
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-2021-18250
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 →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2021-18250↗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-2021-31340 · cve.blacktree.nl