An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. The firmware image contains encrypted passwords that are used to authenticate users wishing to access a diagnostics or password-recovery menu. Using the hardcoded cryptographic key found elsewhere in the firmware, these passwords can be decrypted. This is related to fds_sys_passDebugPasswd_ret() and fds_sys_passRecoveryPasswd_ret() in libfds.so.0.0.
| Software | From | Fixed in |
|---|---|---|
| zyxel / gs1900-8_firmware | - | 2.50\(aahh.0\)c0 |
| zyxel / gs1900-8hp_firmware | - | 2.50\(aahi.0\)c0 |
| zyxel / gs1900-10hp_firmware | - | 2.50\(aazi.0\)c0 |
| zyxel / gs1900-16_firmware | - | 2.50\(aahj.0\)c0 |
| zyxel / gs1900-24e_firmware | - | 2.50\(aahk.0\)c0 |
| zyxel / gs1900-24_firmware | - | 2.50\(aahl.0\)c0 |
| zyxel / gs1900-24hp_firmware | - | 2.50\(aahm.0\)c0 |
| zyxel / gs1900-48_firmware | - | 2.50\(aahn.0\)c0 |
| zyxel / gs1900-48hp_firmware | - | 2.50\(aaho.0\)c0 |