Horizon Alert
Summary of the vulnerability and why it matters
Zyxel USG devices with firmware version 4.60 are vulnerable due to an undocumented administrative account. This account has an unchangeable password that is present in plain text within the firmware, allowing unauthorized access with administrative privileges. Such access could compromise the security and operational integrity of affected organizations.
- Undocumented administrative account
- Unchangeable, cleartext password
- Unauthorized administrative access
Attack Path
How an attacker could exploit the issue
An undocumented account with hardcoded credentials exists within the firmware of affected Zyxel devices. This account is accessible via the SSH server or the web interface. Attackers can leverage this account to gain administrative privileges on the device.
- Network exposure required.
- Attacker logs in with credentials.
- Gains administrative control.
Live Threat
Current exploitation, exposure, and threat context
This vulnerability allows attackers with no special skill level to gain administrative access to Zyxel devices. The exploit requires no specific access or conditions, as it can be exploited remotely over the network. The business risk is critical due to the potential for complete compromise of affected devices, including data interception and manipulation of network traffic.
- Attacker skill: Low.
- Access required: Network access.
- Business risk: Critical.
Priority actions
Operational Fix
Recommended remediation, mitigation, and detection steps
An undocumented administrative account exists in the firmware of multiple Zyxel USG devices. This account can be accessed via SSH or web interface with elevated privileges, posing a significant risk to the confidentiality, integrity, and availability of organizational systems and data. The existence of this account and its credentials within the firmware increases the potential for unauthorized access and control of network devices.
- Identify affected Zyxel devices.
- Restrict network access to these devices.
- Apply vendor updates and confirm resolution.
