CVE-2021-32804
Arbitrary File Creation/Overwrite due to insufficient absolute path sanitization
En resumen
El paquete npm tar no elimina correctamente las rutas absolutas de los archivos durante la extracción, permitiendo que los atacantes creen o sobrescriban archivos en cualquier lugar del sistema usando barras repetidas en las rutas (como ////home/user/.bashrc).
Detalle técnico
La sanitización insuficiente de rutas en node-tar permite la creación/sobrescritura arbitraria de archivos al extraer archivos tar con rutas absolutas maliciosamente construidas que contienen separadores de raíz repetidos. La vulnerabilidad existe porque el código elimina solo una barra inicial, dejando barras posteriores intactas que se resuelven a rutas absolutas. Un atacante puede explotar esto proporcionando un archivo tar especialmente construido sin requerir que la flag `preservePaths` esté habilitada.
Resumen generado y traducido por IA a partir de la descripción oficial.
The npm package "tar" (aka node-tar) before versions 6.1.1, 5.0.6, 4.4.14, and 3.3.2 has a arbitrary File Creation/Overwrite vulnerability due to insufficient absolute path sanitization. node-tar aims to prevent extraction of absolute file paths by turning absolute paths into relative paths when the `preservePaths` flag is not set to `true`. This is achieved by stripping the absolute path root from any absolute file paths contained in a tar file. For example `/home/user/.bashrc` would turn into `home/user/.bashrc`. This logic was insufficient when file paths contained repeated path roots such as `////home/user/.bashrc`. `node-tar` would only strip a single path root from such paths. When given an absolute file path with repeating path roots, the resulting path (e.g. `///home/user/.bashrc`) would still resolve to an absolute path, thus allowing arbitrary file creation and overwrite. This issue was addressed in releases 3.2.2, 4.4.14, 5.0.6 and 6.1.1. Users may work around this vulnerability without upgrading by creating a custom `onentry` method which sanitizes the `entry.path` or a `filter` method which removes entries with absolute paths. See referenced GitHub Advisory for details. Be aware of CVE-2021-32803 which fixes a similar bug in later versions of tar.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N