CVE-2021-32804
Arbitrary File Creation/Overwrite due to insufficient absolute path sanitization
Em resumo
O pacote npm tar não remove corretamente caminhos absolutos de arquivos durante a extração, permitindo que atacantes criem ou sobrescrevam arquivos em qualquer lugar do sistema usando barras repetidas nos caminhos (como ////home/user/.bashrc).
Detalhe técnico
Sanitização insuficiente de caminhos no node-tar permite criação/sobrescrita arbitrária de arquivos ao extrair arquivos tar com caminhos absolutos maliciosamente construídos contendo separadores de raiz repetidos. A vulnerabilidade existe porque o código remove apenas uma barra inicial, deixando barras subsequentes intactas que resolvem para caminhos absolutos. Um atacante pode explorar isso fornecendo um arquivo tar especialmente construído sem exigir que a flag `preservePaths` seja ativada.
Resumo gerado e traduzido por IA a partir da descrição 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