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CVE-2018-19988: D Link Dir 868l Firmware: Command injection

CVE-2018-19988 is rated critical with a CVSS v3.0 base score of 9.8 and NVD lists D Link Dir 868l 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

In the /HNAP1/SetClientInfoDemo message, the AudioMute and AudioEnable parameters are vulnerable, and the vulnerabilities affect D-Link DIR-868L Rev.B 2.05B02 devices. In the SetClientInfoDemo.php source code, the AudioMute and AudioEnble parameters are saved in the ShellPath script file without any regex checking. After the script file is executed, the command injection occurs. It needs to bypass the wget command option with a single quote. A vulnerable /HNAP1/SetClientInfoDemo XML message could have single quotes and backquotes in the AudioMute or AudioEnable element, such as the '`telnetd`' string.

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-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 868l Firmware: 2.05b02

References