Zyxel security advisory for insufficient session expiration and cleartext storage of sensitive information vulnerabilities of NBG6604 home router

CVEs: CVE-2021-35034, CVE-2021-35035

Summary

Zyxel has released a patch addressing insufficient session expiration and cleartext storage of sensitive information vulnerabilities in the NBG6604 home router. Users are advised to install it for optimal protection.

What are the vulnerabilities?

CVE-2021-35034

An insufficient session expiration vulnerability is present due to the CGI program lacking a proper session expiration mechanism.

CVE-2021-35035

A cleartext storage of sensitive information vulnerability is present due to the configuration file lacking a proper permission control mechanism.

What versions are vulnerable—and what should you do?

After a thorough investigation, we’ve identified only one vulnerable product that is within its warranty and support period and released a firmware patch to address these issues, as shown in the table below.

Got a question?

Please contact your local service rep or visit Zyxel’s forum for further information or assistance.

Acknowledgment

Thanks to Liu Yan-Ting for reporting the issues to us.

Revision history

2021-12-30: Initial release