Security readout for executives and security teams
Plain-English summary
This CVE affects WAGO PLC web-based management. If an attacker can reach the WBM interface, the sources say they can read and change device settings without authenticating. For industrial equipment, unauthorized setting changes can create safety, availability, and process integrity risk.
Executive priority
Treat this as urgent for any affected PLC reachable beyond tightly controlled engineering networks. Prioritize exposed or remotely reachable devices first because unauthorized management changes could affect operations.
Technical view
CVE-2021-34578 is a CWE-287 authentication flaw in multiple WAGO PLC models running firmware up to FW07. The reported behavior allows unauthenticated read and write access to settings parameters through specially constructed WBM requests. CVSS 3.1 is 9.8, reflecting network reachability and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely where affected WAGO PLC models expose WBM to plant networks, remote access paths, or the internet, especially on firmware up to FW07. The bundle does not provide CPEs or deployment prevalence.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. The vulnerability is still severe because exploitation requires no credentials if the attacker can access WBM.
Researcher notes
Evidence is limited to the CVE record, CVE List entry, and VDE advisory reference. Do not assume exploit availability, additional affected products, or a specific fixed firmware unless confirmed in vendor guidance.
Mitigation direction
- Identify affected WAGO PLC models and firmware versions in asset inventory.
- Check the VDE/WAGO advisory for vendor-approved firmware updates or compensating controls.
- Restrict WBM access to trusted management networks or VPN-only paths.
- Remove any direct internet exposure for affected PLC management interfaces.
- Monitor for unauthorized configuration changes on affected devices.
Validation and detection
- Confirm whether deployed models match the affected WAGO product list.
- Verify firmware is not within the affected range up to FW07.
- Map all network paths that can reach each device WBM interface.
- Review logs or configuration records for unexpected settings changes.
- Document vendor advisory status and remediation decisions for each asset.
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-287: 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-2021-34578 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
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://cert.vde.com/en-us/advisories/vde-2020-044CVE 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.
Improper Authentication
Improper Authentication represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.