Security readout for executives and security teams
Plain-English summary
Some Siemens SIMATIC controllers can be forced into denial of service by specially crafted traffic to TCP port 102. This is an availability issue for industrial control devices, not a confidentiality or data-theft issue in the cited record.
Executive priority
Treat as a targeted operational resilience issue. It is not rated critical, but affected PLC availability can matter directly to production uptime and safety margins.
Technical view
CVE-2021-44695 affects listed Siemens SIMATIC Drive Controller, ET 200SP Open Controller, S7-1200, and S7-1500 CPU variants below specified fixed versions. The flaw is CWE-1286 and improper processing of crafted packets on 102/tcp, causing device denial of service.
Likely exposure
Exposure is most relevant where affected Siemens controllers have TCP/102 reachable from untrusted, flat, or poorly segmented networks. Internet exposure is not stated in the sources.
Exploitation context
The source bundle marks CISA KEV as false. The CVSS vector includes proof-of-concept exploit maturity, but no cited source confirms active exploitation.
Researcher notes
The record does not provide packet details, exploit steps, or recovery behavior. Validation should stay defensive: version matching, network reachability review, and vendor-advisory comparison.
Mitigation direction
- Upgrade affected Siemens devices to the fixed versions listed by the advisory.
- Review Siemens ProductCERT SSA-382653 before choosing compensating controls.
- Restrict TCP/102 access to required engineering and operations hosts.
- Segment affected controllers from corporate and external networks.
- Prioritize devices supporting safety-critical or production-critical processes.
Validation and detection
- Inventory Siemens SIMATIC controller models and firmware versions.
- Identify devices below the fixed version thresholds in the advisory.
- Check whether TCP/102 is reachable from non-operational networks.
- Review monitoring for unexplained controller resets or availability loss.
- Confirm remediation status after firmware updates or access-control changes.
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-1286: 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-2021-44695 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
- Medium
- CVSS
- 4.9 (3.1)
- Known Exploited
- No
- Published
Vector: 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
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:H/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C1.23.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.9MediumVector: 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
Source materials
- CVE List V5 sourceCVE List V5
- https://cert-portal.siemens.com/productcert/pdf/ssa-382653.pdfCVE 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 Syntactic Correctness of Input
Improper Validation of Syntactic Correctness of Input represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.