CVE-2025-69203

MEDIUM

Signalk Signal K Server < 2.19.0 - Authentication Bypass by Spoofing

Title source: rule

Description

Signal K Server is a server application that runs on a central hub in a boat. Versions prior to 2.19.0 of the access request system have two related features that when combined by themselves and with an information disclosure vulnerability enable convincing social engineering attacks against administrators. When a device creates an access request, it specifies three fields: `clientId`, `description`, and `permissions`. The SignalK admin UI displays the `description` field prominently to the administrator when showing pending requests, but the actual `permissions` field (which determines the access level granted) is less visible or displayed separately. This allows an attacker to request `admin` permissions while providing a description that suggests readonly access. The access request handler trusts the `X-Forwarded-For` HTTP header without validation to determine the client's IP address. This header is intended to preserve the original client IP when requests pass through reverse proxies, but when trusted unconditionally, it allows attackers to spoof their IP address. The spoofed IP is displayed to administrators in the access request approval interface, potentially making malicious requests appear to originate from trusted internal network addresses. Since device/source names can be enumerated via the information disclosure vulnerability, an attacker can impersonate a legitimate device or source, craft a convincing description, spoof a trusted internal IP address, and request elevated permissions, creating a highly convincing social engineering scenario that increases the likelihood of administrator approval. Users should upgrade to version 2.19.0 to fix this issue.

Scores

CVSS v3 6.3
EPSS 0.0002
EPSS Percentile 5.3%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L

Classification

CWE
CWE-290
Status published

Affected Products (6)

signalk/signal_k_server < 2.19.0
signalk/signal_k_server
signalk/signal_k_server
signalk/signal_k_server
signalk/signal_k_server
npm/signalk-server < 2.19.0npm

Timeline

Published Jan 01, 2026
Tracked Since Feb 18, 2026