CVE-2021-32804 – tar

Package

Manager: npm
Name: tar
Vulnerable Version: >=0 <3.2.2 || >=4.0.0 <4.4.14 || >=5.0.0 <5.0.6 || >=6.0.0 <6.1.1

Severity

Level: High

CVSS v3.1: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N

EPSS: 0.85517 pctl0.99329

Details

Arbitrary File Creation/Overwrite due to insufficient absolute path sanitization ### Impact Arbitrary File Creation, Arbitrary File Overwrite, Arbitrary Code Execution `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. ### Patches 3.2.2 || 4.4.14 || 5.0.6 || 6.1.1 NOTE: an adjacent issue [CVE-2021-32803](https://github.com/npm/node-tar/security/advisories/GHSA-r628-mhmh-qjhw) affects this release level. Please ensure you update to the latest patch levels that address CVE-2021-32803 as well if this adjacent issue affects your `node-tar` use case. ### Workarounds 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. ```js const path = require('path') const tar = require('tar') tar.x({ file: 'archive.tgz', // either add this function... onentry: (entry) => { if (path.isAbsolute(entry.path)) { entry.path = sanitizeAbsolutePathSomehow(entry.path) entry.absolute = path.resolve(entry.path) } }, // or this one filter: (file, entry) => { if (path.isAbsolute(entry.path)) { return false } else { return true } } }) ``` Users are encouraged to upgrade to the latest patch versions, rather than attempt to sanitize tar input themselves.

Metadata

Created: 2021-08-03T19:06:36Z
Modified: 2021-08-30T23:14:50Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/08/GHSA-3jfq-g458-7qm9/GHSA-3jfq-g458-7qm9.json
CWE IDs: ["CWE-22"]
Alternative ID: GHSA-3jfq-g458-7qm9
Finding: F063
Auto approve: 1