CVE-2019-15802

MEDIUM

Zyxel GS1900 Series Firmware < 2.50(AAHH.0)C0 - Use of Hard-coded Credentials in Password Encryption

Title source: llm
STIX 2.1

Description

An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. The firmware hashes and encrypts passwords using a hardcoded cryptographic key in sal_util_str_encrypt() in libsal.so.0.0. The parameters (salt, IV, and key data) are used to encrypt and decrypt all passwords using AES256 in CBC mode. With the parameters known, all previously encrypted passwords can be decrypted. This includes the passwords that are part of configuration backups or otherwise embedded as part of the firmware.

References (2)

Core 2
Core References
Exploit, Third Party Advisory x_refsource_misc
https://jasper.la/exploring-zyxel-gs1900-firmware-with-ghidra.html

Scores

CVSS v3 5.9
EPSS 0.0027
EPSS Percentile 50.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Details

CWE
CWE-798
Status published
Products (9)
zyxel/gs1900-10hp_firmware < 2.50\(aazi.0\)c0
zyxel/gs1900-16_firmware < 2.50\(aahj.0\)c0
zyxel/gs1900-24_firmware < 2.50\(aahl.0\)c0
zyxel/gs1900-24e_firmware < 2.50\(aahk.0\)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
zyxel/gs1900-8_firmware < 2.50\(aahh.0\)c0
zyxel/gs1900-8hp_firmware < 2.50\(aahi.0\)c0
Published Nov 14, 2019
Tracked Since Feb 18, 2026