CVE intelligence and bounded remediation

CVE-2023-51440 — Siemens Simatic Cp 343-1 Firmware security vulnerability

High CVSS 7.5

A vulnerability has been identified in SIMATIC CP 343-1 (6GK7343-1EX30-0XE0) (All versions), SIMATIC CP 343-1 Lean (6GK7343-1CX10-0XE0) (All versions), SIPLUS NET CP 343-1 (6AG1343-1EX30-7XE0) (All versions), SIPLUS NET CP 343-1 Lean (6AG1343-1CX10-2XE0) (All versions). Affected products incorrectly validate TCP sequence numbers. This could allow an unauthenticated remote attacker to create a denial of service condition by injecting spoofed TCP RST packets.

Severity
High
CVSS
7.5 (3.1)
Published
2024-02-13
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-940

Affected products

  • siemens / simatic_cp_343-1_firmware
  • siemens / simatic_cp_343-1_lean_firmware
  • siemens / siplus_net_cp_343-1_firmware
  • siemens / siplus_net_cp_343-1_lean_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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