CVE intelligence and bounded remediation

CVE-2018-7830 — Schneider-Electric Modicom M340 Firmware security vulnerability

High CVSS 7.5

Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting') vulnerability exists in the embedded web servers in all Modicon M340, Premium, Quantum PLCs and BMXNOR0200 where a denial of service can occur for ~1 minute by sending a specially crafted HTTP request.

Severity
High
CVSS
7.5 (3.0)
Published
2018-11-30
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-113

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

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

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