CVE intelligence and bounded remediation

CVE-2020-15783 — A vulnerability has been identified in SIMATIC S7-300 CPU family (incl

High CVSS 7.8

A vulnerability has been identified in SIMATIC S7-300 CPU family (incl. related ET200 CPUs and SIPLUS variants) (All versions), SIMATIC TDC CPU555 (All versions), SINUMERIK 840D sl (All versions). Sending multiple specially crafted packets to the affected devices could cause a Denial-of-Service on port 102. A cold restart is required to recover the service.

Severity
High
CVSS
7.8 (2.0)
Published
2020-11-12
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-400

Affected products

  • siemens / sinumerik_840d_sl_firmware
  • siemens / simatic_s7-300_cpu_312_firmware
  • siemens / simatic_s7-300_cpu_314_firmware
  • siemens / simatic_s7-300_cpu_315-2_dp_firmware
  • siemens / simatic_s7-300_cpu_315-2_pn_firmware
  • siemens / simatic_s7-300_cpu_317-2_pn_firmware

Showing 6 representative product identities from 12 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

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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