CVE-2025-71383 in WIFI4
Summary
by MITRE • 10/06/2026
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.
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Analysis
by VulDB Data Team • 10/06/2026
The Dbit WIFI4 N300 router, specifically version 1.0.0, contains a critical stability vulnerability within its web-based management interface that allows for remote denial-of-service attacks from the local network segment. This flaw is triggered when an authenticated or unauthenticated user sends an HTTP request to the login endpoint without including the required username and password fields in the JSON payload. The device's firmware fails to handle this malformed input gracefully, leading to a complete crash of the management service rather than returning a standard error code indicating missing parameters.
At the technical level, the root cause lies within the application-layer JSON parser embedded in the router’s web server implementation. When the parser encounters a request object that is structurally incomplete regarding authentication credentials, it likely attempts to access null or undefined memory pointers associated with those fields. This improper input validation leads to an unhandled exception or segmentation fault within the process handling the HTTP requests. Consequently, the service responsible for managing device configuration and status monitoring terminates unexpectedly, leaving the router in a non-responsive state until the hardware is manually rebooted by an administrator.
The operational impact of this vulnerability is significant for network administrators who rely on continuous access to the device’s management plane. A successful exploit results in a denial-of-service condition where the administrative interface becomes unavailable. This disruption prevents users from monitoring network performance, changing security settings, or troubleshooting connectivity issues. In environments requiring high availability, such as small office or home networks relying on this specific hardware model for internet gateway functions, the inability to access management tools can lead to prolonged downtime and potential misconfiguration if administrators are forced to reset the device to factory defaults without proper backup of current settings.
This vulnerability aligns with Common Weakness Enumeration (CWE) ID 20, which describes Improper Input Validation, as well as CWE 754, indicating an inappropriate check for a rare or exceptional condition that leads to a crash. From a threat modeling perspective, this behavior is consistent with ATT&CK technique T1498, Network Denial of Service, specifically through resource exhaustion via malformed requests. While the attack vector requires access to the local Wi-Fi network, it does not necessarily require prior authentication if the login endpoint processes pre-authentication JSON payloads before verifying credentials.
Mitigation strategies for this vulnerability primarily involve firmware updates provided by Dbit that address the input validation logic in the web server component. Administrators should ensure their devices are running the latest stable firmware version which includes patches for these parser errors. In cases where immediate patching is not possible, network segmentation can be employed to restrict access to the management interface only from trusted IP addresses or VLANs with strict firewall rules that validate HTTP request structures before they reach the device. Additionally, implementing rate limiting on login endpoints may help mitigate the frequency of such crashes if automated scanning tools are detected attempting to exploit this flaw across multiple devices simultaneously.