CVE intelligence and bounded remediation

CVE-2018-21203 — Certain NETGEAR devices are affected by a stack-based buffer overflow by an unauthenticated attacker

High CVSS 8.8

Certain NETGEAR devices are affected by a stack-based buffer overflow by an unauthenticated attacker. This affects R6100 before 1.0.1.20, R9000 before 1.0.2.52, WNDR3700v4 before 1.0.2.96, WNDR4300 before 1.0.2.98, WNDR4300v2 before 1.0.0.50, and WNDR4500v3 before 1.0.0.50.

Severity
High
CVSS
8.8 (3.1)
Published
2020-04-28
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-787

Affected products

  • netgear / r6100_firmware
  • netgear / r9000_firmware
  • netgear / wndr3700_firmware
  • netgear / wndr4300_firmware
  • netgear / wndr4500_firmware

Showing 5 representative product identities from 6 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Buffer bounds, memory safety, and memory corruption

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

Check exposure

  • Identify affected native-code versions, build flags, architectures, parsers, codecs, drivers, and input paths in all shipped artifacts.
  • Determine whether untrusted data reaches the affected routine and the process privilege, sandbox, and network exposure.
  • Confirm statically linked, vendored, firmware, and platform-provided copies, not only package-manager records.

Remediate safely

  • Apply the maintained upstream correction or replace the affected component, then rebuild every dependent artifact from clean inputs.
  • Adopt bounds-checked interfaces, validated sizes and integer conversions, clear ownership, and memory-safe components where practical.
  • Enable supported compiler and runtime hardening and add sanitized tests and fuzz regression seeds derived from non-weaponized fixtures.

Authoritative sources

Complete CVE record and remediation plan

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