Path Traversal in Npm Node-Tar
CVE-2021-32804
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.
Vulnerability class: Path Traversal (Directory Traversal)
EPSS: 0.151 (96.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N.
Affected products
- Npm Node-tar — versions < 3.2.2, >= 4.0.0, < 4.4.14, >= 5.0.0, < 5.0.6
- Oracle Graalvm — versions 20.3.3, 21.2.0
- Siemens Sinec_infrastructure_network_services
- Tar_project Tar
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (Product, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory, Mitigation)
- security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (Third Party Advisory, x_refsource_MISC, Mitigation)
- security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (x_refsource_CONFIRM, Patch, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-32804?
- CVE-2021-32804 is a high-severity vulnerability in Npm Node-Tar, classified under Path Traversal. CVSS score: 8.2/10. Published 2021-08-03.
- How severe is CVE-2021-32804?
- High severity. CVSS v3 base score is 8.2 out of 10.
- Is CVE-2021-32804 known to be exploited?
- 4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.