Security readout for executives and security teams
Plain-English summary
This flaw affects WAGO I/O-Check Service in listed WAGO product families. An unauthenticated remote attacker could trigger a denial of service and limited memory disclosure. The main business risk is disruption to industrial control operations where vulnerable devices are reachable over the network.
Executive priority
Treat as a high-priority operational technology issue if WAGO devices are present. Focus first on reachable systems supporting production, safety-adjacent, or critical facility processes.
Technical view
CVE-2021-34567 is a CWE-125 out-of-bounds read in WAGO I/O-Check Service. CVSS 3.1 is 8.2, with network attack vector, low complexity, no privileges, no user interaction, low confidentiality impact, and high availability impact. The source describes crafted packets containing OS commands but does not provide safe implementation details.
Likely exposure
Exposure is most relevant to organizations using WAGO I/O-Check Service on the listed WAGO product families and FW1 firmware entries. The bundle provides no CPEs, asset prevalence, or internet-exposure evidence.
Exploitation context
The bundle does not identify active exploitation, and KEV status is false. Risk remains meaningful because the CVSS vector indicates unauthenticated remote reachability and low attack complexity, with potential operational downtime.
Researcher notes
The provided evidence supports unauthenticated remote denial of service and limited out-of-bounds read. It does not confirm exploit availability, active exploitation, CPE mappings, or exact fixed versions. Vendor advisory review is necessary before asserting product-specific remediation.
Mitigation direction
- Review the VDE advisory and WAGO guidance for affected firmware and fixes.
- Restrict network access to WAGO I/O-Check Service from untrusted networks.
- Segment industrial control networks from corporate and internet-facing systems.
- Monitor WAGO support channels for firmware or configuration updates.
- Prioritize remediation where device availability supports critical operations.
Validation and detection
- Inventory WAGO devices matching the listed product families and FW1 entries.
- Confirm whether I/O-Check Service is enabled or network-reachable.
- Check firmware versions against the vendor advisory details.
- Review firewall rules and remote access paths to affected devices.
- Look for unexplained service crashes or availability events on exposed controllers.
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-125: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. 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-2021-34567 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
- 8.2 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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:L/I:N/A:H3.94.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.2HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://cert.vde.com/en/advisories/VDE-2020-036/CVE reference
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.
Out-of-bounds Read
Out-of-bounds Read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.