Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:LSummary
CVE-2025-69203 is a medium-severity Authentication Bypass by Spoofing (CWE-290) vulnerability in Signalk Signal K Server. Its CVSS base score is 6.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Adversary-in-the-Middle (T1557); ranked at the 20th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to IA-2 (Identification and Authentication (Organizational Users)) and IA-3 (Device Identification and Authentication) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2025-69203 affects Signal K Server, a server application that runs on a central hub in a boat, specifically versions prior to 2.19.0 in the access request system. The vulnerability arises from two related features: the admin UI prominently displays the `description` field from access requests while making the `permissions` field less visible or separate, allowing attackers to request `admin` permissions with a misleading readonly description; and the access request handler unconditionally trusts the `X-Forwarded-For` HTTP header to determine client IP addresses, enabling IP spoofing. These issues, combined with an information disclosure vulnerability that allows enumeration of device/source names, facilitate convincing social engineering attacks against administrators.
Any network-accessible attacker without privileges can exploit this by crafting an access request that impersonates a legitimate device using an enumerated name, provides a benign `description` suggesting readonly access, requests elevated `admin` permissions, and spoofs a trusted internal IP address via the `X-Forwarded-For` header. This creates a highly convincing approval interface for administrators, who may grant the request due to the apparent legitimacy, resulting in unauthorized elevated access to the server and potential low-level impacts on confidentiality, integrity, and availability as scored by CVSS 6.3 (AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L).
Advisories recommend upgrading to Signal K Server version 2.19.0, which addresses these issues in the access request system, as detailed in the GitHub security advisory (GHSA-vfrf-vcj7-wvr8) and release notes (v2.19.0).
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-206135
Vulnerability Data
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 3 hardening rules · 3 OS baselines
V6.4.3V10.4.16V10.5.1V11.4.3
Mitigating Controls (NIST 800-53 r5) AI
Proper unique identification and authentication of users directly stops spoofing-based bypass of authentication.
Device identification and authentication before connection prevents spoofing of devices to bypass auth.
Authentication of non-organizational users blocks external spoofing attempts against the scheme.
Authenticator management ensures credentials cannot be easily spoofed or reused to bypass authentication.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Protecting, conveying, and verifying identity assertions specifically prevents the spoofing that enables authentication bypass.
Requiring authentication of users/services/hardware directly counters spoofing-based bypass when strong methods are used.
Proofing and binding identities reduces spoofing opportunities during enrollment but does not address runtime authentication implementation flaws.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Secure authentication control directly mitigates authentication bypass by spoofing.
Authentication information management directly addresses credential handling that prevents spoofing.
Security testing can detect spoofing vulnerabilities but does not prevent them by itself.
Access control policy reduces spoofing opportunities but does not prescribe authentication mechanisms.
Identity management supports unique identities but does not guarantee resistance to spoofing.
Access rights assignment limits exposure but does not enforce authentication strength.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (1 rule)
- V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-290
RHEL 7 (1 rule)
- V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. prevents CWE-290
RHEL 8 (1 rule)
- V-230492 RHEL 8 must not have the rsh-server package installed. prevents CWE-290