CVE intelligence and bounded remediation

CVE-2018-8879 — Asus Rt-Ac66U Firmware security vulnerability

Critical CVSS 9.8

Stack-based buffer overflow in Asuswrt-Merlin firmware for ASUS devices older than 384.4 and ASUS firmware before 3.0.0.4.382.50470 for devices allows remote attackers to execute arbitrary code by providing a long string to the blocking.asp page via a GET or POST request. Vulnerable parameters are flag, mac, and cat_id.

Severity
Critical
CVSS
9.8 (3.1)
Published
2019-11-21
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-787

Affected products

  • asus / rt-ac66u_firmware

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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