Security readout for executives and security teams
Plain-English summary
Some Siemens SIMATIC RFID communications modules and readers can be overwhelmed by many incoming connections. If reachable by an attacker, the device may stop serving its operational role, creating a denial-of-service risk for manufacturing, logistics, or identification workflows that depend on those readers.
Executive priority
Treat this as an operational resilience issue, not a confirmed breach indicator. Prioritize plants or facilities where RFID reader outages would disrupt production, logistics, or access workflows.
Technical view
CVE-2021-31340 is a CWE-400 resource-consumption issue in specified Siemens SIMATIC RF devices. The reported failure mode is improper handling of large numbers of incoming connections, allowing denial of service. The bundle does not provide CVSS data, exploit detail, or proof of active exploitation.
Likely exposure
Exposure is mainly sites using the listed Siemens SIMATIC RF166C/RF185C/RF186C/RF188C, RF360R, or RF610R/RF615R/RF650R/RF680R/RF685R reader variants in the affected firmware ranges.
Exploitation context
The source bundle says an attacker may cause denial of service through large numbers of incoming connections. It does not state authentication requirements, network adjacency, public exploit availability, or active exploitation. KEV status is false.
Researcher notes
Evidence is limited to the CVE description and Siemens advisory reference. No CVSS vector, exploit prerequisites, authentication context, or recovery behavior is provided in the source bundle. Avoid assuming internet exploitability without confirming deployment topology.
Mitigation direction
- Identify all deployed Siemens SIMATIC RF devices listed in the advisory.
- Compare firmware versions against the affected ranges in CVE-2021-31340.
- Follow Siemens SSA-787292 for vendor-approved update or mitigation guidance.
- Prioritize devices supporting production, access, inventory, or safety-adjacent workflows.
- Limit unnecessary network reachability to affected devices while remediation is planned.
Validation and detection
- Inventory affected model names and firmware versions from asset records or device management.
- Confirm whether each device falls inside the stated affected version ranges.
- Check Siemens SSA-787292 for the applicable fixed or recommended version path.
- Verify remediation by rechecking firmware versions after change windows.
- Monitor for availability issues involving repeated or abnormal connection spikes.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-400: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-31340 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://cert-portal.siemens.com/productcert/pdf/ssa-787292.pdfCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Uncontrolled Resource Consumption
Uncontrolled Resource Consumption represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.