VULNERABILITY INTELLIGENCE
CVE-2019-15803
Description
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.
Weakness classification
- nvd@nist.gov: CWE-287
Primary references
- cve@mitre.org — Exploit, Third Party Advisory
- cve@mitre.org — Vendor Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Exploit, Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Vendor Advisory