CVE-2018-20834

Name: CVE-2018-20834
Creator: NVD / NIST
Published: 2019-04-30T19:29:03.327+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

UnknownEPSS 3.15%

Last modified Jun 17, 2026

CVE-2018-20834 is a vulnerability of currently unknown severity. A vulnerability was found in node-tar before version 4.4.2 (excluding version 2.2.2). An Arbitrary File Overwrite issue exists when extracting a tarball containing a hardlink to a file that already exists on the system, in conjunction with a later plain file with the same name as the hardlink. EPSS estimates a 3.15% chance of exploitation in the next 30 days.

Description

A vulnerability was found in node-tar before version 4.4.2 (excluding version 2.2.2). An Arbitrary File Overwrite issue exists when extracting a tarball containing a hardlink to a file that already exists on the system, in conjunction with a later plain file with the same name as the hardlink. This plain file content replaces the existing file content. A patch has been applied to node-tar v2.2.2).

Metrics

EPSS Probability

3.15%

86.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-59

Affected Software

Vendor	Product	Versions
Isaacs	Tar	< 2.2.2
Isaacs	Tar	>= 3.0.0, < 4.4.2

References

https://access.redhat.com/errata/RHSA-2019:1821
https://github.com/npm/node-tar/commit/7ecef07da6a9e72cc0c4d0c9c6a8e85b6b52395d
https://github.com/npm/node-tar/commit/b0c58433c22f5e7fe8b1c76373f27e3f81dcd4c8Patch, Third Party Advisory
https://github.com/npm/node-tar/commits/v2.2.2
https://github.com/npm/node-tar/compare/58a8d43...a5f7779Patch, Third Party Advisory
https://hackerone.com/reports/344595Exploit, Third Party Advisory
https://nvd.nist.gov/vuln/detail/CVE-2018-20834
https://access.redhat.com/errata/RHSA-2019:1821
https://github.com/npm/node-tar/commit/7ecef07da6a9e72cc0c4d0c9c6a8e85b6b52395d
https://github.com/npm/node-tar/commit/b0c58433c22f5e7fe8b1c76373f27e3f81dcd4c8Patch, Third Party Advisory
https://github.com/npm/node-tar/commits/v2.2.2
https://github.com/npm/node-tar/compare/58a8d43...a5f7779Patch, Third Party Advisory
https://hackerone.com/reports/344595Exploit, Third Party Advisory
https://nvd.nist.gov/vuln/detail/CVE-2018-20834

Timeline

Published: Apr 30, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-20834?

How severe is CVE-2018-20834?

Severity scoring for CVE-2018-20834 is pending analysis. The EPSS model estimates a 3.15% probability of exploitation in the next 30 days.

How do I fix CVE-2018-20834?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2018-20834?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST