Security readout for executives and security teams
Plain-English summary
An unauthenticated attacker on the same network as Siemens SINEMA Remote Connect Server could trigger sleep notifications to managed devices, causing a denial of service. This is not internet-scale by itself, but it can be business-relevant in OT environments where device availability affects operations.
Executive priority
Treat this as a moderate OT availability risk. Prioritize remediation where SINEMA Remote Connect Server manages operationally important devices or shares network access with less-trusted systems.
Technical view
CVE-2021-37183 affects SINEMA Remote Connect Server versions before V3.0 SP2. The issue is mapped to CWE-284 and allows abuse of send-to-sleep notifications from an adjacent network position. CVSS 3.1 is 6.5, with high availability impact and no confidentiality or integrity impact stated.
Likely exposure
Exposure is likely limited to organizations running Siemens SINEMA Remote Connect Server before V3.0 SP2 where an attacker can reach the affected system from the same network segment or adjacent network path.
Exploitation context
The provided sources do not report active exploitation, and KEV is false. The attack requires same-network access, but no authentication, privileges, or user interaction are required according to the CVSS vector.
Researcher notes
The source evidence describes denial of service through unauthenticated abuse of sleep notifications, not data theft or code execution. Public evidence in the bundle is limited to the CVE data and Siemens advisory reference.
Mitigation direction
- Upgrade SINEMA Remote Connect Server to V3.0 SP2 or later where applicable.
- Review Siemens advisory SSA-334944 for vendor-specific remediation guidance.
- Restrict access to the SINEMA Remote Connect Server management network.
- Segment OT management traffic from untrusted user and device networks.
- Monitor managed devices for unexpected sleep or availability events.
Validation and detection
- Inventory all SINEMA Remote Connect Server deployments and record versions.
- Confirm whether any instance runs a version earlier than V3.0 SP2.
- Map which hosts can reach the affected server from adjacent networks.
- Review logs for unexpected send-to-sleep notifications or availability disruptions.
- Verify compensating network controls block untrusted adjacent access.
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-284: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. 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-2021-37183 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
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/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:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H2.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://cert-portal.siemens.com/productcert/pdf/ssa-334944.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.
Improper Access Control
Improper Access Control represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.