Описание
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 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
Ссылки
- 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/releases/tag/v1.7.1
Пакеты
Наименование
shescape
npm
Затронутые версииВерсия исправления
< 1.7.1
1.7.1
Связанные уязвимости
CVSS3: 3.1
nvd
больше 2 лет назад
Shescape is a simple shell escape library for JavaScript. An attacker may be able to get read-only access to environment variables. This bug has been patched in version 1.7.1.