6.4 Medium
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:L/Au:N/C:P/I:P/A:N
9.1 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
9.3 High
AI Score
Confidence
High
0.011 Low
EPSS
Percentile
84.8%
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.
6.4 Medium
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:L/Au:N/C:P/I:P/A:N
9.1 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
9.3 High
AI Score
Confidence
High
0.011 Low
EPSS
Percentile
84.8%