Quantum Secular Labs / Blog / Advisories

CVE-2017-18046: Dasannetworks H640x Firmware: Buffer overflow

CVE-2017-18046 is rated critical with a CVSS v3.0 base score of 9.8 and NVD lists Dasannetworks H640x Firmware as the affected product. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability 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).

Severity breakdown

CVSS v3.0 9.8: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Unchanged. Impact stays within the vulnerable component.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary.

Affected products

  • Dasannetworks H640x Firmware: 2.77p1-1124; 3.03p2-1146; 12.02-01121

References