Security readout for executives and security teams
Plain-English summary
This flaw could let an unauthenticated remote attacker create user accounts on certain WAGO managed switches. For executives, the concern is loss of control over industrial network infrastructure: unauthorized access could affect confidentiality, integrity, and availability of connected operations.
Executive priority
Treat this as urgent for operational technology and industrial environments. A successful attack could create unauthorized switch access without credentials, making rapid inventory, exposure reduction, and vendor-guided remediation a high-priority control action.
Technical view
CVE-2021-20998 is a CWE-306 missing-authentication issue in multiple WAGO managed switch models. The record states specially crafted packets can create users without authorization. CVSS 3.1 is 10.0 with network access, low complexity, no privileges, and no user interaction required.
Likely exposure
Exposure is most likely where listed WAGO managed switch models are deployed and reachable over management or operational networks. The source bundle lists affected models but does not provide exact vulnerable firmware ranges, so asset and firmware verification against vendor guidance is required.
Exploitation context
The provided sources support unauthenticated network attack potential, but do not document public exploitation or in-the-wild abuse. The CVE is not marked as CISA KEV in the supplied bundle. Do not assume active exploitation without newer authoritative evidence.
Researcher notes
Evidence is limited to CVE metadata and the VDE advisory reference in the bundle. The affected versions are unspecified, and no exploit details or patch version are included. Validation should focus on asset identification, vendor advisory comparison, and account/configuration review.
Mitigation direction
- Identify whether listed WAGO switch models are present in your environment.
- Review the VDE/WAGO advisory for fixed versions or official compensating controls.
- Restrict switch management access to trusted administrative networks only.
- Remove affected management interfaces from internet or untrusted network exposure.
- Contact WAGO support if firmware applicability is unclear.
Validation and detection
- Inventory WAGO models 0852-0303, 0852-1305, 0852-1505, and listed variants.
- Compare installed firmware and configuration against the VDE advisory.
- Review switch user accounts for unknown or unauthorized entries.
- Confirm management interfaces are not reachable from untrusted networks.
- Document remediation status for each affected switch.
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-306: Credential and account abuse lookup
Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. 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-2021-20998 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
- Critical
- CVSS
- 10 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/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:C/C:H/I:H/A:H3.96Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
10CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://cert.vde.com/en-us/advisories/vde-2021-013CVE reference · x_refsource_CONFIRM
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.
Missing Authentication for Critical Function
Missing Authentication for Critical Function represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.