CVE intelligence and bounded remediation

CVE-2017-11420 — Asuswrt-Merlin Project Rt-Ac5300 Firmware security vulnerability

Critical CVSS 9.8

Stack-based buffer overflow in ASUS_Discovery.c in networkmap in Asuswrt-Merlin firmware for ASUS devices and ASUS firmware for ASUS RT-AC5300, RT_AC1900P, RT-AC68U, RT-AC68P, RT-AC88U, RT-AC66U, RT-AC66U_B1, RT-AC58U, RT-AC56U, RT-AC55U, RT-AC52U, RT-AC51U, RT-N18U, RT-N66U, RT-N56U, RT-AC3200, RT-AC3100, RT_AC1200GU, RT_AC1200G, RT-AC1200, RT-AC53, RT-N12HP, RT-N12HP_B1, RT-N12D1, RT-N12+, RT_N12+_PRO, RT-N16, and RT-N300 devices allows remote attackers to execute arbitrary code via long device information that is mishandled during a strcat to a device list.

Severity
Critical
CVSS
9.8 (3.0)
Published
2017-07-18
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-119

Affected products

  • asuswrt-merlin_project / rt-ac5300_firmware
  • asuswrt-merlin_project / rt_ac1900p_firmware
  • asuswrt-merlin_project / rt-ac68u_firmware
  • asuswrt-merlin_project / rt-ac68p_firmware
  • asuswrt-merlin_project / rt-ac88u_firmware
  • asuswrt-merlin_project / rt-ac66u_firmware

Showing 6 representative product identities from 28 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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