Zyxel security advisory for insufficient entropy vulnerability for web authentication tokens......

Zyxel_May

Zyxel security advisory for insufficient entropy vulnerability for web authentication tokens generation in GS1900 series switches

CVE: CVE-2024-38270

Summary

Zyxel has released patches for GS1900 series switches affected by an insufficient entropy vulnerability. Users are advised to install them for optimal protection.

What is the vulnerability?

An insufficient entropy vulnerability caused by the improper use of a randomness function with low entropy for web authentication tokens generation was found in the Zyxel GS1900 series switch firmware. This vulnerability could allow a LAN-based attacker to guess a valid session token if multiple authenticated sessions are alive.

What versions are vulnerable—and what should you do?

After a thorough investigation, we have identified the vulnerable products that are within their vulnerability support period, with their firmware patches shown in the table below.

Affected model	Affected version	Patch availability
GS1900-8	V2.80(AAHH.0)C0	V2.80(AAHH.1)C0
GS1900-8HP	V2.80(AAHI.0)C0	V2.80(AAHI.1)C0
GS1900-10HP	V2.80(AAZI.0)C0	V2.80(AAZI.1)C0
GS1900-16	V2.80(AAHJ.0)C0	V2.80(AAHJ.1)C0
GS1900-24	V2.80(AAHL.0)C0	V2.80(AAHL.1)C0
GS1900-24E	V2.80(AAHK.0)C0	V2.80(AAHK.1)C0
GS1900-24EP	V2.80(ABTO.0)C0	V2.80(ABTO.1)C0
GS1900-24HPv2	V2.80(ABTP.0)C0	V2.80(ABTP.1)C0
GS1900-48	V2.80(AAHN.0)C0	V2.80(AAHN.1)C0
GS1900-48HPv2	V2.80(ABTQ.0)C0	V2.80(ABTQ.1)C0

Got a question?

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

Acknowledgment

Thanks to Steinar H. Gunderson for reporting the issue to us.

Revision history

2024-9-10: Initial release