Security readout for executives and security teams
Plain-English summary
This Siemens SIMATIC controller flaw can let a highly privileged network attacker disrupt affected devices by sending specially crafted traffic to TCP port 102. The main business impact is operational interruption, not data theft. Affected firmware should be identified and upgraded using Siemens guidance.
Executive priority
Prioritize remediation where affected controllers support production, safety, or high-availability operations. The score is medium, but outage impact in industrial environments can justify near-term action, especially if TCP/102 is widely reachable.
Technical view
CVE-2021-44694 is a CWE-1287 input validation issue in multiple Siemens SIMATIC controllers. Affected devices mishandle certain crafted packets sent to 102/tcp, causing denial of service. CVSS 3.1 is 5.5 with network attack vector, low complexity, high privileges required, no user interaction, integrity low, and availability high impact.
Likely exposure
Exposure is likely limited to environments running listed Siemens SIMATIC S7-1200, S7-1500, Drive Controller, or ET 200SP Open Controller models below the fixed firmware versions, especially where TCP/102 is reachable from engineering or management networks.
Exploitation context
The bundle does not show CISA KEV listing or active exploitation. The CVSS vector lists exploit maturity as proof-of-concept, but high privileges are required. Treat internet or broadly reachable TCP/102 access as higher operational risk.
Researcher notes
Evidence is strongest for affected products, fixed-version thresholds, port, impact, and CVSS characteristics. The provided bundle does not include exploit details, active exploitation evidence, or complete operational workaround text beyond the Siemens advisory reference.
Mitigation direction
- Inventory affected Siemens controller models and firmware versions.
- Upgrade affected products to the fixed versions named in the advisory.
- Use Siemens SSA-382653 for product-specific update and mitigation guidance.
- Restrict TCP/102 exposure to approved engineering and management systems.
- Plan updates through operational change control to avoid production disruption.
Validation and detection
- Compare each controller firmware version against the affected-version thresholds.
- Confirm TCP/102 reachability is limited to authorized network paths.
- Verify Siemens advisory guidance has been applied for each product family.
- After updates, re-check firmware inventory for fixed versions.
- Review operational monitoring for unexplained controller denial-of-service symptoms.
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-1287: 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-2021-44694 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
- 5.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/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:L/A:H/E:P/RL:O/RC:C1.24.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/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 Specified Type of Input
Improper Validation of Specified Type of Input represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.