CVE intelligence and bounded remediation

CVE-2018-7812 — Schneider-Electric Modicom M340 Firmware security vulnerability

High CVSS 7.5

An Information Exposure through Discrepancy vulnerability exists in the embedded web servers in all Modicon M340, Premium, Quantum PLCs and BMXNOR0200 where the web server sends different responses in a way that exposes security-relevant information about the state of the product, such as whether a particular operation was successful or not.

Severity
High
CVSS
7.5 (3.0)
Published
2018-12-17
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-200

Affected products

  • schneider-electric / modicom_m340_firmware
  • schneider-electric / modicom_premium_firmware
  • schneider-electric / modicom_quantum_firmware
  • schneider-electric / modicom_bmxnor0200h_firmware

Matched remediation archetype

Information disclosure and sensitive data exposure

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace sensitive data through responses, errors, logs, metrics, traces, caches, exports, files, backups, and client bundles.
  • Identify affected subjects, tenants, retention windows, access controls, and downstream copies without opening unnecessary sensitive records.
  • Review metadata, timing, status, length, and existence signals as well as direct content disclosure.

Remediate safely

  • Minimize collection and output, apply field-level authorization and redaction at a centralized boundary, and return generic external errors.
  • Remove secrets and sensitive data from logs, artifacts, URLs, caches, and client-side bundles; rotate credentials that may have been exposed.
  • Update the affected component and add synthetic-data tests for response, error, observability, and export paths.

Authoritative sources

Complete CVE record and remediation plan

The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.