GHSA-3g7p-8qhx-mc8r Shescape potential environment variable exposure on Windows with CMD

• npm shescape: < 1.7.1 → fixed in 1.7.1

Impact This impact users of Shescape: 1. On Windows using the Windows Command Prompt (i.e. `cmd.exe`), and 2. 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: ```javascript 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 // And interpolation: true, // Only applies to `escape` and `escapeAll` usage } // 2. Attack (one of many) const payload = "%PATH%"; // 3. Usage let escapedPayload; escapedPayload = shescape.quote(payload, options); // Or escapedPayload = shescape.quoteAll([payload], options); // Or escapedPayload = shescape.escape(payload, options); // Or escapedPayload = shescape.escapeAll([payload], options); // And (example) const result = cp.execSync(`echo Hello ${escapedPayload}`, options); // 4. Impact console.log(result.toString()); // Outputs "Hello" followed by the contents of the PATH environment variable ``` 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