Security readout for executives and security teams
Plain-English summary
This CVE affects specific WAGO industrial controllers and can let an unauthenticated network attacker make the device unavailable. The reported impact is availability only, not data theft or code execution. For operations that depend on these controllers, the business risk is production disruption.
Executive priority
Prioritize remediation where affected controllers support production, safety-adjacent operations, or remote facilities. Treat internet or broadly reachable devices as urgent because exploitation requires no credentials.
Technical view
CVE-2021-34581 is a CWE-772 resource lifetime issue in the OpenSSL implementation of WAGO 750-831, 750-880, 750-881, and 750-889 devices, reported for FW4 through FW15. CVSS 3.1 is 7.5: network reachable, low complexity, no privileges or user interaction, high availability impact.
Likely exposure
Exposure is most likely in OT or industrial environments running the named WAGO controller families on affected firmware, especially if the device is reachable from untrusted networks or broad internal segments.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. The vulnerability is remotely reachable and unauthenticated, but the documented outcome is denial of service rather than compromise.
Researcher notes
Evidence is limited to the CVE record and VDE advisory reference in the provided bundle. No exploit details, patch version, or vendor workaround text was provided, so remediation should be confirmed against current WAGO/VDE guidance.
Mitigation direction
- Inventory affected WAGO controller models and firmware versions.
- Check WAGO and VDE advisory guidance for supported fixes or mitigations.
- Restrict device network reachability to trusted management and OT hosts.
- Segment affected controllers from enterprise and internet-accessible networks.
- Monitor affected controllers for availability drops or unexpected resets.
Validation and detection
- Confirm whether any listed WAGO models exist in the environment.
- Record firmware versions and compare them with FW4 through FW15 exposure.
- Review network paths to determine who can reach affected controller services.
- Verify monitoring detects controller unavailability quickly.
- Document vendor advisory status and planned remediation actions.
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-772: Exact CWE lookup
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Open ATT&CK lookupCVE-2021-34581 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
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/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:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://cert.vde.com/en-us/advisories/vde-2021-038CVE 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 Release of Resource after Effective Lifetime
Missing Release of Resource after Effective Lifetime represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.