CVE intelligence and bounded remediation

CVE-2017-18046 — Dasannetworks H640X Firmware security vulnerability

Critical CVSS 9.8

Buffer overflow on Dasan GPON ONT WiFi Router H640X 12.02-01121 2.77p1-1124 and 3.03p2-1146 devices allows remote attackers to execute arbitrary code via a long POST request to the login_action function in /cgi-bin/login_action.cgi (aka cgipage.cgi).

Severity
Critical
CVSS
9.8 (3.0)
Published
2018-01-21
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-119

Affected products

  • dasannetworks / h640x_firmware / 2.77p1-1124
  • dasannetworks / h640x_firmware / 3.03p2-1146
  • dasannetworks / h640x_firmware / 12.02-01121

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

The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.