CVE-2020-29583
Published on December 22, 2020
Firmware version 4.60 of Zyxel USG devices contains an undocumented account (zyfwp) with an unchangeable password. The password for this account can be found in cleartext in the firmware. This account can be used by someone to login to the ssh server or web interface with admin privileges.
Known Exploited Vulnerability
This ZyXEL Unified Security Gateway Undocumented Administrator Account with Default Credentials vulnerability is part of CISA's list of Known Exploited Vulnerabilities. Firmware version 4.60 of ZyXEL USG devices contains an undocumented account (zyfwp) with an unchangeable password.
The following remediation steps are recommended / required by May 3, 2022: Apply updates per vendor instructions.
Vulnerability Analysis
CVE-2020-29583 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. This vulnerability is known to be actively exploited by threat actors in an automatable fashion. The potential impact of an exploit of this vulnerability is considered to be critical as this vulnerability has a high impact to the confidentiality, integrity and availability of this component.
Weakness Type
Insufficiently Protected Credentials
The product transmits or stores authentication credentials, but it uses an insecure method that is susceptible to unauthorized interception and/or retrieval.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.