CVE intelligence and bounded remediation

CVE-2019-6843 — Schneider-Electric Modicon M580 Firmware security vulnerability

Medium CVSS 4.9

A CWE-755: Improper Handling of Exceptional Conditions vulnerability exists in Modicon M580 with firmware (version prior to V3.10), Modicon M340 (all firmware versions), and Modicon BMxCRA and 140CRA modules (all firmware versions), which could cause a Denial of Service attack on the PLC when upgrading the controller with an empty firmware package using FTP protocol.

Severity
Medium
CVSS
4.9 (3.1)
Published
2019-10-29
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-755

Affected products

  • schneider-electric / modicon_m580_firmware
  • schneider-electric / modicon_m340_firmware
  • schneider-electric / modicon_bmxcra_firmware
  • schneider-electric / modicon_140cra_firmware

Matched remediation archetype

Resource exhaustion and denial of service

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

Check exposure

  • Identify attacker-influenced work factors including input size, nesting, compression, fan-out, regex cost, allocation, recursion, retries, and connection lifetime.
  • Map per-request and shared CPU, memory, disk, descriptor, thread, queue, and downstream-service limits.
  • Determine whether authentication, tenancy, quotas, and rate controls apply before expensive processing begins.

Remediate safely

  • Bound input size, nesting, expansion, work, concurrency, queue depth, retries, and execution time before resource-intensive processing.
  • Release resources on every success, error, cancellation, and timeout path and use backpressure instead of unbounded buffering.
  • Update affected components and add small deterministic tests that assert resource ceilings rather than exhausting a host.

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.