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Ie Wl Bl Ap Cl Eu FirmwareOperating system · Weidmueller

CVE-2021-33535

HIGH · 8.8 CVSS v3.1 Published 2021-06-25
Fix available
A fix is available. Upgrade to after 1.16.18 or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In Weidmueller Industrial WLAN devices in multiple versions an exploitable format string vulnerability exists in the iw_console conio_writestr functionality. A specially crafted time server entry can cause an overflow of the time server buffer, resulting in remote code execution. An attacker can send commands while authenticated as a low privilege user to trigger this vulnerability.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A format string vulnerability exists in the iw_console conio_writestr function of Weidmueller Industrial WLAN devices. Authenticated low-privilege users can trigger the vulnerability by providing specially crafted input to the time server configuration, causing a buffer overflow that can lead to remote code execution.

MitigationApply vendor-supplied firmware patches when available; in the interim, restrict network access to the device management interface and implement network segmentation to limit exposure to authenticated attackers.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Ie Wl Bl Ap Cl Eu FirmwareOperating system
Affected:<= 1.16.18<= 1.11.10
Ie Wlt Bl Ap Cl Eu FirmwareOperating system
Affected:<= 1.16.18<= 1.11.10
Ie Wl Bl Ap Cl Us FirmwareOperating system
Affected:<= 1.16.18<= 1.11.10
Ie Wlt Bl Ap Cl Us FirmwareOperating system
Affected:<= 1.16.18<= 1.11.10
Ie Wl Vl Ap Br Cl Eu FirmwareOperating system
Affected:<= 1.16.18<= 1.11.10
Ie Wlt Vl Ap Br Cl Eu FirmwareOperating system
Affected:<= 1.16.18<= 1.11.10
Ie Wl Vl Ap Br Cl Us FirmwareOperating system
Affected:<= 1.16.18<= 1.11.10
Ie Wlt Vl Ap Br Cl Us FirmwareOperating system
Affected:<= 1.16.18<= 1.11.10

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify device model
    Locate the Weidmueller Industrial WLAN device model number on the physical device label or in the management interface. Match it against the affected product list: Ie Wl Bl Ap Cl Eu, Ie Wlt Bl Ap Cl Eu, Ie Wl Bl Ap Cl Us, Ie Wlt Bl Ap Cl Us, Ie Wl Vl Ap Br Cl Eu, Ie Wlt Vl Ap Br Cl Eu, Ie Wl Vl Ap Br Cl Us, or Ie Wlt Vl Ap Br Cl Us.
    Affected if Device model matches one of the eight listed Weidmueller Industrial WLAN variants
  2. Check firmware version
    Access the device web interface or CLI and navigate to the firmware version information page, typically under System > Status or similar. Record the installed firmware version number.
    Affected if Firmware version is <= 1.16.18 or <= 1.11.10
  3. Verify iw_console module is active
    Check if the iw_console component is running on the device. This may be visible in the device management interface under Modules, or accessible via CLI command such as 'iw_console status' or by inspecting running processes.
    Affected if The iw_console module is loaded and running on the device
  4. Confirm time server configuration access
    Navigate to the time server or NTP configuration section in the device management interface. Determine whether this configuration panel is accessible to authenticated users with low privileges (non-admin).
    Affected if Time server configuration is accessible to authenticated low-privilege users

Device is affected if it is a Weidmueller Industrial WLAN variant with firmware <= 1.16.18 or <= 1.11.10, the iw_console module is active, and the time server configuration is accessible to authenticated low-privilege users.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to a release after 1.16.18
Interim mitigation

Apply vendor-supplied firmware patches when available; in the interim, restrict network access to the device management interface and implement network segmentation to limit exposure to authenticated attackers.

Fix this in Ie Wl Bl Ap Cl Eu Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-33535 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data