Medium · 5.3 CVE-2025-6599 EUVD-2025-197903GHSA-r99r-5wp8-8w99

An uncontrolled resource consumption vulnerability in the web server of Zyxel DX3301-T0 firmware version 5.50(ABVY.6.3)C0 and earlier could…

Published Nov 18, 2025 · Updated Nov 18, 2025 · Assigned by Zyxel

Vendor: Zyxel Product: DX3301-T0 firmware Category: Network devices

Description

An uncontrolled resource consumption vulnerability in the web server of Zyxel DX3301-T0 firmware version 5.50(ABVY.6.3)C0 and earlier could allow an attacker to perform Slowloris‑style denial‑of‑service (DoS) attacks. Such attacks may temporarily block legitimate HTTP requests and partially disrupt access to the web management interface, while other networking services remain unaffected.

Affected products

Vendor	Product	Affected	Fixed
Zyxel	DX3301-T0 firmware	<= 5.50(ABVY.6.3)C0	—

References

https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-uncontrolled-resource-consumption-and-command-injection-vulnerabilities-in-certain-4g-lte-5g-nr-cpe-dsl-ethernet-cpe-fiber-onts-security-routers-and-wireless-extenders-11-18-2025 vendor-advisory