RUSTSEC-2018-0002

Links in archives can overwrite any existing file

Reported

June 29, 2018

Issued

October 1, 2020 (last modified: June 13, 2023)

Package

tar (crates.io)

Type

Vulnerability

Keywords

#file-overwrite

Aliases

References

https://github.com/alexcrichton/tar-rs/pull/156

CVSS Score

7.5 HIGH

CVSS Details

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: High
Availability: None

CVSS Vector

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

Patched

>=0.4.16

Description

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 available under CC0-1.0 license.