| CVE-2019-15803 | Date: (C)2019-11-15 (M)2023-12-22 |
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.
CVSS Score and Metrics +CVSS Score and Metrics -| CVSS V3 Severity: | CVSS V2 Severity: |
| CVSS Score : 9.1 | CVSS Score : 6.4 |
| Exploit Score: 3.9 | Exploit Score: 10.0 |
| Impact Score: 5.2 | Impact Score: 4.9 |
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| CVSS V3 Metrics: | CVSS V2 Metrics: |
| Attack Vector: NETWORK | Access Vector: NETWORK |
| Attack Complexity: LOW | Access Complexity: LOW |
| Privileges Required: NONE | Authentication: NONE |
| User Interaction: NONE | Confidentiality: PARTIAL |
| Scope: UNCHANGED | Integrity: PARTIAL |
| Confidentiality: HIGH | Availability: NONE |
| Integrity: HIGH | |
| Availability: NONE | |
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