Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:HSummary
CVE-2025-66398 is a critical-severity OS Command Injection (CWE-78) vulnerability in Signalk Signal K Server. Its CVSS base score is 9.6 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 3% of CVEs by exploit likelihood; 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 AC-3 (Access Enforcement) and AC-6 (Least Privilege) — 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-2025-66398 affects Signal K Server, an application that runs on central hubs in boats, in versions prior to 2.19.0. The vulnerability enables an unauthenticated attacker to pollute the server's internal state, specifically the `restoreFilePath` variable, through the `/skServer/validateBackup` endpoint. This manipulation hijacks the administrator's "Restore" functionality, allowing overwrite of critical configuration files such as `security.json` and `package.json`. The issue is associated with CWE-78 (Improper Neutralization of Special Elements used in an OS Command) and CWE-913 (Improper Control of Dynamically-Managed Code Resources), earning a CVSS v3.1 base score of 9.6 (AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H).
An unauthenticated remote attacker can exploit this vulnerability by sending crafted requests to the `/skServer/validateBackup` endpoint, requiring subsequent user interaction from an administrator who triggers the restore process. Successful exploitation leads to account takeover by altering security configurations and remote code execution (RCE) through modifications to files like `package.json`, granting full control over the server.
The Signal K Server release notes for version 2.19.0 and the associated GitHub security advisory (GHSA-w3x5-7c4c-66p9) confirm that updating to v2.19.0 fully patches the vulnerability by addressing the state pollution in the validateBackup endpoint. Security practitioners should prioritize upgrading affected boat hub installations to mitigate risks in maritime environments.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-206140
Vulnerability Data
Signal K Server is a server application that runs on a central hub in a boat. Prior to version 2.19.0, an unauthenticated attacker can pollute the internal state (`restoreFilePath`) of the server via the `/skServer/validateBackup` endpoint. This allows the attacker…
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to hijack the administrator's "Restore" functionality to overwrite critical server configuration files (e.g., `security.json`, `package.json`), leading to account takeover and Remote Code Execution (RCE). Version 2.19.0 patches this vulnerability.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 2 hardening rules · 2 OS baselines
V1.2.5V1.2.8V15.2.5
Mitigating Controls (NIST 800-53 r5) AI
Access enforcement directly stops unauthorized reads/writes to dynamic code resources by applying authorization checks at access time.
Least privilege reduces the set of subjects that can reach or modify dynamic code resources, limiting the weakness's reach.
Developer testing and evaluation can discover missing or incorrect command sanitization during development.
Input validation directly neutralizes or rejects special characters that would otherwise alter OS command structure.
Least functionality restricts available OS commands and interpreters, limiting the blast radius of injection.
Secure engineering principles require proper neutralization of untrusted input before command construction.
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.
Secure SDLC practices explicitly include controls that prevent improper handling of dynamic code resources.
Blocking unauthorized code execution directly limits the ability to abuse dynamically-managed resources.
Runtime-environment monitoring can detect exploitation of the weakness but does not prevent it.
Vulnerability identification can surface instances of CWE-913 but does not mitigate the root weakness.
Hardened configuration baselines can restrict dynamic code execution and variable access at runtime.
Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).
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.
Security testing and code review target insecure use of operating-system command interfaces, catching command-injection flaws introduced during development.
Secure development lifecycle mandates controls on dynamic code generation and resource management.
Application security requirements explicitly address restrictions on dynamic code execution and resource access.
Secure architecture principles require design controls that prevent improper dynamic code resource manipulation.
Secure coding standards directly prohibit unsafe dynamic code resource handling and injection patterns.
Environment separation reduces exposure of dynamic code resources but does not address the underlying weakness.
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).
Windows 10 (1 rule)
- V-220726 Data Execution Prevention (DEP) must be configured to at least OptOut. prevents CWE-913
Windows 11 (1 rule)
- V-253283 Data Execution Prevention (DEP) must be configured to at least OptOut. prevents CWE-913