An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. User accounts created through the web interface of the device, when given non-admin level privileges, have the same level of privileged access as administrators when connecting to the device via SSH (while their permissions via the web interface are in fact restricted). This allows normal users to obtain the administrative password by running the tech-support command via the CLI: this contains the encrypted passwords for all users on the device. As these passwords are encrypted using well-known and static parameters, they can be decrypted and the original passwords (including the administrator password) can be obtained.
This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 8.8, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction requiring only low-level privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), and availability (service disruption) for affected systems. Impacting 18 products from zyxel, from zyxel, from zyxel and 15 others, organizations running these solutions should prioritize assessment and patching.
First disclosed in 2019, this vulnerability was reported during a period defined by widespread IoT adoption challenges, mobile security concerns, and the emergence of advanced persistent threat (APT) techniques. Contemporary mitigation strategies focused on secure development practices and third-party component vetting.
2019-11-14T21:15:11.623
2024-11-21T04:29:29.333
Modified
CVSSv3.1: 8.8 (HIGH)
AV:N/AC:L/Au:S/C:C/I:C/A:C
8.0
10.0
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Operating System | zyxel | gs1900-8_firmware | < 2.50\(aahh.0\)c0 | Yes |
| Hardware | zyxel | gs1900-8 | - | No |
| Operating System | zyxel | gs1900-8hp_firmware | < 2.50\(aahi.0\)c0 | Yes |
| Hardware | zyxel | gs1900-8hp | - | No |
| Operating System | zyxel | gs1900-10hp_firmware | < 2.50\(aazi.0\)c0 | Yes |
| Hardware | zyxel | gs1900-10hp | - | No |
| Operating System | zyxel | gs1900-16_firmware | < 2.50\(aahj.0\)c0 | Yes |
| Hardware | zyxel | gs1900-16 | - | No |
| Operating System | zyxel | gs1900-24e_firmware | < 2.50\(aahk.0\)c0 | Yes |
| Hardware | zyxel | gs1900-24e | - | No |
| Operating System | zyxel | gs1900-24_firmware | < 2.50\(aahl.0\)c0 | Yes |
| Hardware | zyxel | gs1900-24 | - | No |
| Operating System | zyxel | gs1900-24hp_firmware | < 2.50\(aahm.0\)c0 | Yes |
| Hardware | zyxel | gs1900-24hp | - | No |
| Operating System | zyxel | gs1900-48_firmware | < 2.50\(aahn.0\)c0 | Yes |
| Hardware | zyxel | gs1900-48 | - | No |
| Operating System | zyxel | gs1900-48hp_firmware | < 2.50\(aaho.0\)c0 | Yes |
| Hardware | zyxel | gs1900-48hp | - | No |
SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For zyxel's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.