#VU58204 Path traversal in tar - CVE-2021-37713

Vulnerability identifier: #VU58204

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-37713

CWE-ID: CWE-22

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
tar
Web applications / JS libraries

Vendor: npm Inc.

Description

The vulnerability allows a remote attacker to overwrite arbitrary files on the system.

The vulnerability exists due insufficient logic on Windows systems when extracting tar files that contained a path that was not an absolute path, but specified a drive letter different from the extraction target, such as C:some\path. If the drive letter does not match the extraction target, for example D:\extraction\dir, then the result of path.resolve(extractionDirectory, entryPath) would resolve against the current working directory on the C: drive, rather than the extraction target directory.

Mitigation
Install update from vendor's website.

Vulnerable software versions

tar: 4.0.0 - 6.1.8

---

External links
https://github.com/npm/node-tar/security/advisories/GHSA-5955-9wpr-37jh

---

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.