CVE-2019-15804 - Zyxel Gs1900-24hp Firmware, Zyxel Gs1900-10hp Firmware and Zyxel Gs1900-8 Firmware

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.

Affected software

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