Quantum Secular Labs / Blog / Advisories

CVE-2018-25115: D-Link Dir 815 Firmware: Command injection

CVE-2018-25115 is rated critical with a CVSS v3.1 base score of 9.8 and affects D-Link Dir 815 Firmware, along with 6 other products in NVD’s configuration data. 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

Multiple D-Link DIR-series routers, including DIR-110, DIR-412, DIR-600, DIR-610, DIR-615, DIR-645, and DIR-815 firmware version 1.03, contain a vulnerability in the service.cgi endpoint that allows remote attackers to execute arbitrary system commands without authentication. The flaw stems from improper input handling in the EVENT=CHECKFW parameter, which is passed directly to the system shell without sanitization. A crafted HTTP POST request can inject commands that are executed with root privileges, resulting in full device compromise. These router models are no longer supported at the time of assignment and affected version ranges may vary. Exploitation evidence was first observed by the Shadowserver Foundation on 2025-08-21 UTC.

Severity breakdown

CVSS v3.1 9.8: CVSS:3.1/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-78: Improper Neutralization of Special Elements used in an OS Command

The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command before it is sent to a downstream component.

Affected products

  • D-Link Dir 815 Firmware: 1.03
  • D-Link Dir 110 Firmware: all versions listed by NVD
  • D-Link Dir 412 Firmware: all versions listed by NVD
  • D-Link Dir 600 Firmware: all versions listed by NVD
  • D-Link Dir 610 Firmware: all versions listed by NVD
  • D-Link Dir 615 Firmware: all versions listed by NVD
  • D-Link Dir 645 Firmware: all versions listed by NVD

References