CVE-2019-15804

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...

CVE-2019-15802

An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. The firmware hashes and encrypts passwords using a hardcoded cryptographic key in sal_util_str_encrypt() in libsal.so.0.0. The parameters (salt, IV, and key data) are used to encrypt and decrypt all passwords using...

CVE-2019-15803

An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. Through an undocumented sequence of keypresses, undocumented functionality is triggered. A diagnostics shell is triggered via CTRL-ALT-t, which prompts for the password returned by fds_sys_passDebugPasswd_ret(). Th...

CVE-2019-15800

An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. Due to lack of input validation in the cmd_sys_traceroute_exec(), cmd_sys_arp_clear(), and cmd_sys_ping_exec() functions in the libclicmd.so library contained in the firmware, an attacker could leverage these funct...

CVE-2019-15799

An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. User accounts created through the web interface of the device, when given non-admin level privileges, have the same level of privileged access as administrators when connecting to the device via SSH (while their pe...

CVE-2019-15801

An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. The firmware image contains encrypted passwords that are used to authenticate users wishing to access a diagnostics or password-recovery menu. Using the hardcoded cryptographic key found elsewhere in the firmware, ...