Modicon M340 Bmxp342020 FirmwareOperating system · Schneider Electric

CVE-2021-22785

HIGH · 7.5 CVSS v3.1 Published 2022-02-11
Fix available
A fix is available. Upgrade to 3.40 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click Patch available

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
A CWE-200: Information Exposure vulnerability exists that could cause sensitive information of files located in the web root directory to leak when an attacker sends a HTTP request to the web server of the device. Affected Product: Modicon M340 CPUs: BMXP34 (Versions prior to V3.40), Modicon M340 X80 Ethernet Communication Modules: BMXNOE0100 (H), BMXNOE0110 (H), BMXNOC0401, BMXNOR0200H RTU (All Versions), Modicon Premium Processors with integrated Ethernet (Copro): TSXP574634, TSXP575634, TSXP576634 (All Versions), Modicon Quantum Processors with Integrated Ethernet (Copro): 140CPU65xxxxx (All Versions), Modicon Quantum Communication Modules: 140NOE771x1, 140NOC78x00, 140NOC77101 (All Versions), Modicon Premium Communication Modules: TSXETY4103, TSXETY5103 (All Versions)

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
How this class of weakness works · CWE-200

The application discloses data — error detail, internal paths, tokens, or other users' records — to someone who shouldn't see it. On its own it can look minor, but it hands attackers the map they need for a larger attack. Remediation is about minimising what's returned and enforcing authorization on every piece of data.

General guidance for the information exposure class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

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
Modicon M340 Bmxp342020 FirmwareOperating system
Affected:< 3.40
Bmxnoe0100 FirmwareOperating system
Affected:all versions
Bmxnoe0110 FirmwareOperating system
Affected:all versions
Bmxnoc0401 FirmwareOperating system
Affected:all versions
Bmxnor0200h Rtu FirmwareOperating system
Affected:all versions
Tsxp574634 FirmwareOperating system
Affected:all versions
Tsxp575634 FirmwareOperating system
Affected:all versions
Tsxp576634 FirmwareOperating system
Affected:all versions

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

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

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.

dbcve · scoped
Upgrade available Upgrade to 3.40 or later
Fixed in 3.40
Recommended fix Moderate confidence

Modicon M340 BMXP342020: Firmware V3.40; Other affected modules: firmware update per SEVD-2021-257-02

  1. 1. Identify the specific Modicon M340 CPU or communication module model number from the affected product list (BMXP34, BMXNOE0100, BMXNOE0110, BMXNOC0401, BMXNOR0200H RTU, TSXP574634, TSXP575634, TSXP576634).
  2. 2. For BMXP342020: Upgrade firmware to version 3.40 or later to remediate the vulnerability.
  3. 3. For all other affected products (BMXNOE0100, BMXNOE0110, BMXNOC0401, BMXNOR0200H RTU, TSXP57xxxx series): Obtain the firmware update from Schneider Electric via the security notification SEVD-2021-257-02 at https://download.schneider-electric.com/files?p_Doc_Ref=SEVD-2021-257-02.
  4. 4. Follow Schneider Electric's standard firmware update procedure for the specific device, ensuring the process is performed during a planned maintenance window.
  5. 5. After updating, verify the web server no longer exposes sensitive files from the web root directory through HTTP requests.
Caveat Firmware updates on industrial control devices should be tested in a non-production environment before deployment; ensure adequate backup and rollback procedures are in place

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,250. Get the upgrade done

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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-2021-22785 in production — separate from our analysis above.

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What this is

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