CVE-2017-18046: Buffer overflow on Dasan GPON ONT WiFi Router H640X 12.02-01121 2.77p1-1124 and 3.03p2-1146 devices allows remote att…

Is it exploited?

Reported, not confirmed by CISA. VulnCheck KEV lists it as exploited in the wild. CISA has not added it to its Known Exploited Vulnerabilities catalog as of 29 Oct 2026.

VulnCheck KEV lists it since 12 Feb 2018. It cites 26 public reports, the first from 12 Feb 2018.

How likely is exploitation in the next 30 days?

EPSS score, percentile 92.3 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

Not scored

The CVE record carries no CVSS score.

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

The CVE record links no vendor advisory, patch or mitigation.

Which versions are affected?

Not stated. The CVE record gives vendor and product as “n/a” and the version as “unspecified”.

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; VulnCheck KEV, as of 30 Oct 2026; FIRST EPSS, as of 30 Oct 2026; CVE List, as of 30 Oct 2026. About the data.

Description

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).

Source: CVE List, as of 30 Oct 2026. About the data.

What to do

Advisories and patches

The CVE record links no vendor advisory, patch or mitigation.

This summary is based on the CVE record as of 30 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

The CVE record does not name affected products or versions: vendor and product are “n/a” and the version is “unspecified”.