// For flags

CVE-2019-15803

 

Severity Score

9.1
*CVSS v3.1

Exploit Likelihood

< 1%
*EPSS

Affected Versions

9
*CPE

Public Exploits

1
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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.

Se descubrió un problema en los dispositivos Zyxel GS1900 con firmware anterior a la versión 2.50 (AAHH.0) C0. A través de una secuencia indocumentada de pulsaciones de teclas, se activa la funcionalidad no documentada. Se activa un shell de diagnóstico a través de CTRL-ALT-t, que solicita la contraseña devuelta por fds_sys_passDebugPasswd_ret (). El firmware contiene comprobaciones de control de acceso que determinan si los usuarios remotos pueden acceder a esta funcionalidad. La función que realiza esta comprobación (fds_sys_remoteDebugEnable_ret en libfds.so) siempre devuelve VERDADERO sin realizar comprobaciones reales. El menú de diagnóstico permite leer / escribir registros arbitrarios y varios otros parámetros de configuración que se cree que están relacionados con los chips de la interfaz de red.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2019-08-29 CVE Reserved
  • 2019-11-14 CVE Published
  • 2024-08-05 CVE Updated
  • 2024-08-05 First Exploit
  • 2025-03-30 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
CWE
  • CWE-287: Improper Authentication
CAPEC
Affected Vendors, Products, and Versions (9)