#VU71631 Link following in node-tar - CVE-2018-20834

Vulnerability identifier: #VU71631

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-2018-20834

CWE-ID: CWE-59

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
node-tar
Web applications / JS libraries

Vendor: isaacs

Description

The vulnerability allows a remote attacker to compromise the affected system.

The vulnerability exists due to insecure following of hardlinks inside a tarball. A remote attacker can pass a specially crafted archive to the application and overwrite arbitrary files on the system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

node-tar: 0.1.0 - 4.4.1

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External links
https://access.redhat.com/errata/RHSA-2019:1821
https://github.com/npm/node-tar/commit/7ecef07da6a9e72cc0c4d0c9c6a8e85b6b52395d
https://github.com/npm/node-tar/commit/b0c58433c22f5e7fe8b1c76373f27e3f81dcd4c8
https://github.com/npm/node-tar/commits/v2.2.2
https://github.com/npm/node-tar/compare/58a8d43...a5f7779
https://hackerone.com/reports/344595

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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.