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CVE-2018-20990 — HIGH Links in tar — CVE Details

HIGH

Links in archives can overwrite any existing file

Published June 29, 2018Updated November 8, 2023Source: osv

Summary

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!

Advisory Timeline

  • First published June 29, 2018 (3027 days ago).
  • Last revised November 8, 2023 — 1958 days after initial publication.

Remediation

Upgrade to the fixed version using your package manager.

Cargo
Update tar to 0.4.16 or later
cargo update -p tar --precise 0.4.16

After upgrading, run your dependency scanner again to confirm the vulnerability is resolved.

Affected Packages (1)

Affects 1 ecosystem: crates.io (1).

PackageEcosystemAffectedFixed In
tar
crates.io
All versions0.4.16

CVSS Score Breakdown

What the CVSS (Common Vulnerability Scoring System) 7.5 score means for each attack dimension.

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

References

Frequently Asked Questions

What is CVE-2018-20990?
Links in archives can overwrite any existing file This vulnerability has been assigned a severity rating of HIGH (CVSS score: 7.5/10).
How do I check if my project is affected by CVE-2018-20990?
CVE-2018-20990 affects tar. Use GeekWala's free vulnerability scanner to check your dependencies against CVE-2018-20990 and 200,000+ other known vulnerabilities.

Severity & Exploitability

CVSS Score
7.5

High exploitability or significant impact. Prioritize remediation within days.

Also Known As

RUSTSEC-2018-0002
GHSA-2367-c296-3mp2

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