Description

Shescape potential environment variable exposure on Windows with CMD

Impact

This impact users of Shescape:

On Windows using the Windows Command Prompt (i.e. cmd.exe), and

Using quote/quoteAll or escape/escapeAll with the interpolation option set to true.

An attacker may be able to get read-only access to environment variables. Example:

import * as cp from "node:child_process";
import * as shescape from "shescape";

// 1. Prerequisites
const options = {
    shell: "cmd.exe",
    // Or
    shell: undefined, // Only if the default shell is CMD...
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Patches

This bug has been patched in v1.7.1 which you can upgrade to now. No further changes are required.

Workarounds

Alternatively, users can remove all instances of % from user input, either before or after using Shescape.

References

Shescape Pull request #982

Shescape commit d0fce70

Shescape Release v1.7.1

Mitigation

Aliases

References