wakaru is a JavaScript decompiler and unminifier toolkit. From 1.0.0 until 1.4.0, @wakaru/cli sanitizes bundle-controlled module filenames only once before writing extracted modules, so a crafted filename containing overlapping traversal sequences such as ....// collapses to ../ after sanitization and lets the final output path escape the selected output directory, allowing an attacker who can cause a user to run wakaru --unpack on a malicious bundle to write files outside that directory and, depending on the target path and environment, potentially achieve code execution. This issue is fixed in @wakaru/cli 1.4.0.

Affected: npm: @wakaru/cli

### Impact

`@wakaru/cli` is vulnerable to arbitrary file write when unpacking a crafted JavaScript bundle with `--unpack`.

Bundle-controlled module filenames were sanitized before writing extracted modules to the output directory. A crafted filename containing overlapping path traversal characters, such as `....//`, could be transformed into `../` after sanitization. This allowed the final output path to escape the intended output directory.

An attacker who can cause a user to run `wakaru --unpack` on a malicious bundle may be able to write files outside the selected output directory. Depending on the target path and user environment, this may lead to code execution.

Affected versions: `>=1.0.0 <1.4.0`.

### Patches

The issue has been patched in `@wakaru/cli@1.4.0`.

Users should upgrade to:

```sh npm install @wakaru/cli@latest ```

or specifically: ``` npm install @wakaru/cli@1.4.0 ```

### Workarounds

Do not run `wakaru --unpack` on untrusted or unknown bundles with affected versions.

If upgrading immediately is not possible, avoid using `--unpack on files that may be attacker-controlled.