CVE-2018-20990

mediumpriority · track · 31EPSS 0.017 · 77 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

1.68% (77th) EPSS

CVSS 6.4 · medium

Is it mine?

4 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · osv · nvd

EPSS · scored 2026-10-27

An issue was discovered in the tar crate before 0.4.16 for Rust. Arbitrary file overwrite can occur via a symlink or hardlink in a TAR archive.

cvss

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.4–7.5

v2.06.4mediumAV:N/AC:L/Au:N/C:N/I:P/A:Pprimary · NVD / NIST USexploitability 10 · impact 4.9

v3.07.5highCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.07.5highCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:Nsecondary · OSV

v3.06.9mediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-59USprimaryCWE-59US

affected products (4)

Products and version ranges known to be affected.

n/a n/a≤ n/aenisa_euvdEU
tar project tar< 0.4.16nvdUScpe:2.3:a:tar_project:tar:*:*:*:*:*:*:*:*
crates.io tar< 0.4.16osvUSpkg:cargo/tar
crates.io tar0.0.0-0 → 0.4.16osvUSpkg:cargo/tar

advisories (2)

Vendor and ecosystem advisories describing this.

GHSA-2367-c296-3mp2Arbitrary file overwrite in tar-rs2021-08-25ghsa · osvUS
When unpacking a tarball with the unpack_in-family of functions it's intended that only files within the specified directory are able to be written. Tarballs with hard links or symlinks, however, can be used to overwrite any file on the filesystem. Tarballs can contain multiple entries for the same file. A tarball which first contains an entry for a hard link or symlink pointing to any file on the filesystem will have the link created, and then afterwards if the same file is listed in the tarball the hard link will be rewritten and any file can be rewritten on the filesystem.
RUSTSEC-2018-0002Links in archives can overwrite any existing file2018-06-29vendor · osvUS
When unpacking a tarball with the `unpack_in`-family of functions it's intended that only files within the specified directory are able to be written. Tarballs with hard links or symlinks, however, can be used to overwrite any file on the filesystem. Tarballs can contain multiple entries for the same file. A tarball which first contains an entry for a hard link or symlink pointing to any file on the filesystem will have the link created, and then afterwards if the same file is listed in the tarball the hard link will be rewritten and any file can be rewritten on the filesystem. This has been fixed in https://github.com/alexcrichton/tar-rs/pull/156 and is published as `tar` 0.4.16. Thanks to Max Justicz for discovering this and emailing about the issue!

also known as (5)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd osv nvd NVD CVE.org MITRE

published 2019-08-26modified 2026-06-17

related (2,373)

Related entries.

ID	severity	EPSS	exploitable	published
CVE-2026-81963US	high7.8OT critical	0.39% (33rd)	KEV	2026-09-08
Improper link resolution before file access ('link following') in Windows Update Stack allows an authorized attacker to elevate privileges locally.
CVE-2026-41091US	—OT critical	8.20% (95th)	KEV	2026-05-20
Improper link resolution before file access ('link following') in Microsoft Defender allows an authorized attacker to elevate privileges locally.
CVE-2025-60710US	—OT critical	4.61% (92nd)	KEV	2025-11-11
Improper link resolution before file access ('link following') in Host Process for Windows Tasks allows an authorized attacker to elevate privileges locally.
CVE-2025-48384US	—OT critical	4.38% (91st)	KEV	2025-07-08
Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals. When reading…
CVE-2025-21391US	—OT critical	2.28% (83rd)	KEV	2025-02-11
Windows Storage Elevation of Privilege Vulnerability

+2368 more

references (4)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan