CVE-2019-15804 Information

Description

An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. By sending a signal to the CLI process undocumented functionality is triggered. Specifically a menu can be triggered by sending the SIGQUIT signal to the CLI application (e.g. through CTRL+\ via SSH). The access control check for this menu does work and prohibits accessing the menu which contains \Password recovery for specific user\ options. The menu is believed to be accessible using a serial console.

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Reference

https://jasper.la/exploring-zyxel-gs1900-firmware-with-ghidra.html https://www.zyxel.com/support/gs1900-switch-vulnerabilities.shtml

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

HIGH

Base Score

NONE

Base Severity

7.5