CVE-2026-23515: @signalk/set system time Remote Code Execution Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-p8gp-2w28-mhwg",
  "modified" : "2026-02-03T16:12:17Z",
  "published" : "2026-02-02T18:10:32Z",
  "aliases" : [ "CVE-2026-23515" ],
  "summary" : "Signal K set-system-time plugin vulnerable to RCE - Command Injection",
  "details" : "### Summary\nA Command Injection vulnerability allows authenticated users with write permissions to execute arbitrary shell commands on the Signal K server when the set-system-time plugin is enabled. Unauthenticated users can also exploit this vulnerability if security is disabled on the Signal K server. This occurs due to unsafe construction of shell commands when processing `navigation.datetime` values received via WebSocket delta messages.\n\n### Details\n**Product:** Signal K set-system-time plugin  \n**Repository:** https://github.com/SignalK/set-system-time  \n\nFile: `index.js`, lines 60-71\n\n```javascript\n      stream.onValue(function (datetime) {\n        var child\n        if (process.platform == 'win32') {\n          console.error(\"Set-system-time supports only linux-like os's\")\n        } else {\n          if( ! plugin.useNetworkTime(options) ){\n            const useSudo = typeof options.sudo === 'undefined' || options.sudo\n            const setDate = `date --iso-8601 -u -s \"${datetime}\"`  // ← VULNERABLE\n            const command = useSudo\n              ? `if sudo -n date &> /dev/null ; then sudo ${setDate} ; else exit 3 ; fi`\n              : setDate\n            child = require('child_process').spawn('sh', ['-c', command])  // ← EXECUTES SHELL\n```\n\nThe vulnerability has three components:\n\n1. **Unsanitized Input**: The `datetime` value from `navigation.datetime` Signal K path is directly interpolated into a shell command without validation\n2. **Shell Execution**: The command is executed via `spawn('sh', ['-c', command])`, which interprets shell metacharacters\n3. **Sudo Privileges**: The plugin can execute with root privileges if `sudo` is misconfigured, instructions to limit passwordless sudo to the /bin/date binary helps mitigate this but RCE can still be achieved with the privileges of the user that installed it.\n\n### PoC\n#### Exploitation Requirements\n\n- Signal K server with security enabled, if disabled credentials not required\n- Valid user credentials with `readwrite` or `admin` permissions\n- set-system-time plugin installed and enabled\n- Signal K server installed on a Linux OS\n- Passwordless sudo configured, official instructions will do this for the `date` command which is enough to satisfy the if condition\n\n\n```Python\n\"\"\"\nRun provided POC:\n    python3 poc.py --host signalkserver_IP -u username -p password\n\nPayload: Creates /tmp/signalk-RCE.txt to prove code execution\n\"\"\"\n```\n\n### Impact\nAn attacker that has write privileges either through security on the Signal K server being disabled or valid credentials with read/write permissions can execute arbitrary commands on the server with the privileges of the SignalK process or root if sudo is misconfigured. This enables complete system compromise.\n\n### Recommendations\n\n- Replace shell-based execution with child_process.execFile() so user-controlled input is passed as arguments rather than interpreted by a shell.\n\n- Validate that navigation.datetime conforms to an expected ISO-8601 format to improve robustness.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@signalk/set-system-time"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.5.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/SignalK/signalk-server/security/advisories/GHSA-p8gp-2w28-mhwg"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-23515"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/SignalK/set-system-time/commit/75b11eae2de528bf89ede3fb1f7ed057ddbb4d24"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/SignalK/signalk-server"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-78" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-02-02T18:10:32Z",
    "nvd_published_at" : "2026-02-02T23:16:07Z"
  }
}