Cybersecurity experts reported the finding of a critical vulnerability in multiple Zyxel routers. According to the report, successful exploitation of this flaw would allow malicious hackers to bypass the device’s authentication process.

Below is a detailed report of the reported flaw, in addition to its CVE identification key and its severity score according to the Common Vulnerability Scoring System (CVSS).

Tracked as CVE-2020-28899, this flaw exists due to an error while processing authentication requests, which allow remote threat actors to bypass authentication process by accessing a set of GCI scripts, gaining unauthorized access to the affected system.

This is a high severity flaw that received a score of 8.5/10 according to the CVSS scale.

The flaw resides in the following versions of Zyxel implementations:

  • LTE4506-M606: before 1.00 ABDO.6 C0
  • LTE7460-M608: before 1.00 ABFR.5 C0
  • WAH7706: before 1.00 ABBC.11 C0

While this flaw can be exploited by unauthenticated remote threat actors over the local network, the cybersecurity experts have not detected active exploitation attempts or malware variants associated with the attack.

Security patches are now available, so users of affected deployments are advised to update as soon as possible. To learn more about information security risks, malware, vulnerabilities and information technologies, feel free to access the International Institute of Cyber Security (IICS) website.