Impact This vulnerability is a command injection issue. When user-controlled input is passed into the format option of the screenshot function, it is interpolated into a shell command without sanitization. An attacker can craft malicious input such as:

{ format: "; echo vulnerable > /tmp/hello;" }

This results in arbitrary command execution with the privileges of the calling process.

Who is impacted: Any application that accepts untrusted input and forwards it directly (or indirectly) into the format option is affected. If the library is used in a server-side context (e.g., API endpoints, web services), attackers may be able to exploit this remotely and without authentication, leading to full compromise of confidentiality, integrity, and availability.

CVSS v3.1 Base Score: 9.8 (Critical) CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Patches The issue has been patched in version 1.15.2. All users are strongly recommended to upgrade to 1.15.2 or later. All earlier versions are vulnerable.

Workarounds If upgrading is not immediately possible, developers should: - Strictly validate or whitelist acceptable format values (e.g., "jpeg", "png", "webp"). - Reject or sanitize any unexpected input before passing it to the library. - Avoid allowing user-controlled data to reach the format option.

References - CWE-78: OS Command Injection - OWASP: Command Injection