Dbit WIFI4 N300: Denial of service in web management interface via malformed login request
Summary
Dbit WIFI4 N300 routers with firmware 1.0.0 can have their web management interface crashed by a request to /api/login that lacks the username or password field. The flaw is caused by a JSON parser error. An attacker needs to be on the local Wi-Fi network, and no login is required; the result is a denial of service rather than a demonstrated compromise. The NVD CVSS score of 9.8 conflicts with the description and with EUVD's 5.8 score, so the real risk is likely lower than the NVD score suggests.
Affected
- Dbit WIFI4 N300, firmware version 1.0.0
- Other firmware versions: Unknown.
Fixed in
Unknown. No fixed firmware version has been published by the vendor.
Workaround
- Place the router's management interface on a separate admin VLAN or restrict admin access to trusted IP addresses.
- Do not allow guest Wi-Fi to reach the router's web interface.
- Disable remote/WAN management and any port forwarding to the device.
Exploitation
- Proof of concept: The Klogix blog documents the discovery and exploitation work for this CVE and CVE-2025-71384; no standalone public PoC for this CVE was found.
- CISA SSVC: Exploitation poc, automatable yes, technical impact total.
- CISA KEV: not listed.
Our recommendation
- Identify all Dbit WIFI4 N300 devices, including those installed by ISPs or bought online.
- Restrict management access to an admin VLAN or trusted IP addresses and block guest Wi-Fi access to the router.
- Disable remote management and port forwarding to the device.
- Monitor for repeated crashes or unexpected reboots.
- Plan replacement with a vendor that provides security updates if the vendor cannot confirm a fix.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Klogix Security: Anatomy of an IoT Exploit (Folie a Deux) www.klogixsecurity.com
- NVD record mirror (Vulners): CVE-2025-71383 vulners.com
- EUVD-2025-211036 (Vulners) vulners.com
- CISA ADP Vulnrichment mirror (HOL Guard): CVE-2025-71383 hol.org
- Strix: CVE-2025-71383 www.strix.ai
- INCIBE-CERT early warning: CVE-2025-71383 www.incibe.es
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 30 Oct 2026, 21:06.
Original description (NVD)
Dbit WIFI4 N300 1.0.0 devices allow the management interface to be crashed via a request (from the local Wi-Fi network) that lacks a /api/login username or password field. This occurs because of an error in a JSON parser.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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