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CVE Record

CVE-2021-27388: SINAMICS medium voltage routable products are affected by a vulnerability in the Sm@rtServer component for...

SINAMICS medium voltage routable products are affected by a vulnerability in the Sm@rtServer component for remote access that could allow an unauthenticated attacker to cause a denial-of-service condition, and/or execution of limited configuration modifications and/or execution of limited control commands on the SINAMICS Medium Voltage Products, Remote Access (SINAMICS SL150: All versions, SINAMICS SM150: All versions, SINAMICS SM150i: All versions).

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

This vulnerability affects the remote access component of specified SINAMICS medium-voltage products. An unauthenticated attacker with network reachability could disrupt operation or perform limited configuration or control actions. The source bundle does not provide CVSS scoring or confirmed fix details, so urgency should be driven by exposure of these systems.

Executive priority

Prioritize within operational technology risk management, especially for critical drive systems. The main business concern is disruption or limited unauthorized control of medium-voltage equipment. Action should focus first on exposure reduction and vendor-confirmed remediation status.

Technical view

CVE-2021-27388 is a CWE-20 improper input validation issue in the Sm@rtServer remote access component for SINAMICS SL150, SM150, and SM150i, listed as all versions. Reported impacts include denial of service, limited configuration modification, and limited control commands. The bundle provides no exploit details, CVSS vector, or patch version.

Likely exposure

Exposure is most likely where SINAMICS SL150, SM150, or SM150i remote access is enabled and reachable over plant, corporate, vendor, or internet-routable networks.

Exploitation context

The bundle states unauthenticated attack potential but does not cite active exploitation. CISA KEV status is false in the provided data. Treat internet or vendor-accessible Sm@rtServer paths as higher risk until vendor guidance and local exposure are verified.

Researcher notes

The available source data is sparse: all affected listed product versions, CWE-20, and impact categories are provided, but no CVSS, technical root-cause detail, exploit status, or remediation version is included. Avoid assuming patch availability without reviewing the referenced advisory and Siemens guidance.

Mitigation direction

  • Identify SINAMICS SL150, SM150, and SM150i assets using remote access.
  • Check Siemens and CISA advisory guidance for supported fixes or mitigations.
  • Restrict remote access to trusted management networks and approved vendor paths.
  • Disable unnecessary Sm@rtServer or remote access functionality where operationally feasible.
  • Monitor affected devices for service disruption or unauthorized configuration changes.

Validation and detection

  • Inventory SINAMICS medium-voltage products and confirm model and remote access status.
  • Verify whether Sm@rtServer is enabled on each affected system.
  • Confirm network reachability from corporate, vendor, and external access paths.
  • Review logs or operational records for unexpected control or configuration events.
  • Document compensating controls if no vendor fix is confirmed.
Prepared
Confidence
medium
Sources
3

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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

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cwe · low confidence lookup

CWE-20: Exact CWE lookup

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cve · low confidence lookup

CVE-2021-27388 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

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.

0CVSS vectors
0Timeline events
0ADP providers
2Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/aSINAMICS Medium Voltage Products, Remote AccessSINAMICS SL150: All versions, SINAMICS SM150: All versions, SINAMICS SM150i: All versionsListed
Weakness

CWE details

CWE-20

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-20 · source CWE mapping

Improper Input Validation

Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs