CVSS 3.1
9.1 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NCVE-2019-15803
Critical (9.1) in zyxel. EPSS 1.3% chance of exploitation in the next 30 days.
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(). The firmware contains access control checks that determine if remote users are allowed to access this functionality. The function that performs this check (fds_sys_remoteDebugEnable_ret in libfds.so) always return TRUE with no actual checks performed. The diagnostics menu allows for reading/writing arbitrary registers and various other configuration parameters which are believed to be related to the network interface chips.
Severity
- EPSS
- 1.3% chance of exploitation in the next 30 days; higher than 70% of CVEs (scores of 2026-10-31)
- CWE
- CWE-287
- Published
- Modified
- Record from
- the NVD, synced
Affected
- zyxel:gs1900-10hp_firmware
- zyxel:gs1900-16_firmware
- zyxel:gs1900-24_firmware
- zyxel:gs1900-24e_firmware
- zyxel:gs1900-24hp_firmware
- zyxel:gs1900-48_firmware
- zyxel:gs1900-48hp_firmware
- zyxel:gs1900-8_firmware
- zyxel:gs1900-8hp_firmware