Security readout for executives and security teams
Plain-English summary
Some Siemens embedded and industrial connectivity products may mishandle malformed ICMP network traffic. A remote, unauthenticated sender could trigger denial-of-service effects and limited information leakage. Business urgency is highest where affected devices are reachable from untrusted networks or support production operations.
Executive priority
Treat as a high-priority OT exposure review, especially for Siemens devices in production environments. The main business risk is outage or degradation from unauthenticated network traffic, with limited confidentiality risk also reported.
Technical view
CVE-2021-31346 is unchecked ICMP payload length validation using the IP header value. Siemens reports possible information leak and denial-of-service depending on memory buffer layout. CVSS 3.1 is 8.2, network exploitable, low complexity, no privileges, no user interaction, with high availability impact.
Likely exposure
Exposure is likely limited to organizations running listed Siemens products: Capital Embedded AR Classic 431-422, Capital Embedded AR Classic R20-11 before V2303, PLUSCONTROL 1st Gen, and SIMOTICS CONNECT 400 below the listed fixed version thresholds.
Exploitation context
The bundle does not show CISA KEV listing or cited evidence of active exploitation. The vulnerability is still operationally relevant because it is remotely reachable over the network and can affect availability without authentication.
Researcher notes
Evidence is limited to CVE and Siemens advisory references in the supplied bundle. The exact side effect depends on memory buffer organization, so validation should focus on product/version exposure and network reachability rather than assuming uniform impact across all deployments.
Mitigation direction
- Inventory the listed Siemens products and record exact installed versions.
- Update products beyond the affected version ranges where Siemens provides fixed releases.
- For all-version affected products, review the relevant Siemens advisory for compensating guidance.
- Restrict ICMP reachability to affected devices from untrusted networks.
- Prioritize segmentation for devices supporting production or safety-adjacent operations.
Validation and detection
- Compare asset versions against the affected product list and version thresholds.
- Confirm affected devices are not reachable from internet or broad corporate networks.
- Review firewall and segmentation rules controlling ICMP to industrial networks.
- Check monitoring for unexplained device resets, hangs, or availability events.
- Document exceptions where vendor fixes are unavailable or unsupported.
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-1284: 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-2021-31346 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
- High
- CVSS
- 8.2 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
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 vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H3.94.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.2HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://cert-portal.siemens.com/productcert/pdf/ssa-114589.pdfCVE reference · x_refsource_MISC
- https://cert-portal.siemens.com/productcert/pdf/ssa-044112.pdfCVE reference · x_refsource_MISC
- https://cert-portal.siemens.com/productcert/pdf/ssa-620288.pdfCVE reference · x_refsource_MISC
- https://cert-portal.siemens.com/productcert/pdf/ssa-845392.pdfCVE reference · x_refsource_MISC
- https://cert-portal.siemens.com/productcert/pdf/ssa-223353.pdfCVE reference · x_refsource_MISC
- https://cert-portal.siemens.com/productcert/html/ssa-114589.htmlCVE reference
- https://cert-portal.siemens.com/productcert/html/ssa-044112.htmlCVE reference
- https://cert-portal.siemens.com/productcert/html/ssa-620288.htmlCVE reference
- https://cert-portal.siemens.com/productcert/html/ssa-845392.htmlCVE reference
- https://cert-portal.siemens.com/productcert/html/ssa-223353.htmlCVE reference
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.
Improper Validation of Specified Quantity in Input
Improper Validation of Specified Quantity in Input represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.