GHSA-xx64-wwv2-hcqq RUSTSEC-2026-0113

astral-tokio-tar: `unpack_in` can chmod arbitrary directories by following symlinks

Low crates.io

Severity: 0.0 / 10; Low · CVSS 4.0
Exploit chance (EPSS): —; No score published
Known exploited: No; Not in CISA's catalog
Weakness: CWE-61 UNIX Symbolic Link (Symlink) Following
Fix: 0.6.1; Upgrade astral-tokio-tar to this version or later

Description

Impact

In versions 0.6.0 and earlier of astral-tokio-tar, the unpack_in API could inadvertently modify the permissions of external (i.e. non-archive) directories outside of the archive. An attacker could use this to contrite a tar archive that maliciously changes directory permissions outside of its intended hierarchy. This flaw only affects directories; individual file permissions cannot be modified via it.

See GHSA-j4xf-2g29-59ph for the equivalent flaw in the tar crate.

Patches

Versions 0.6.1 and newer of astral-tokio-tar use fs::symlink_metdata rather than fs::metadata, avoiding the traversal.

Workarounds

Users are advised to upgrade to version 0.6.1 or newer to address this advisory.

Users should experience no breaking changes as a result of the patch above.

Resources

GHSA-j4xf-2g29-59ph for the original tar vulnerability

Attribution

Reporter: Adam Harvey (@lawngnome)

Affected versions

crates.io

Package	Vulnerable	Fixed in
astral-tokio-tar	`< 0.6.1`	`0.6.1`
astral-tokio-tar	`>= 0.0.0-0, < 0.6.1`	`0.6.1`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

astral-tokio-tar crates.io → `0.6.1`

cargo

cargo update -p astral-tokio-tar --precise 0.6.1

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U

Attack vector: Network
Attack complexity: Low
Attack requirements: None
Privileges required: None
User interaction: None
Confidentiality (vulnerable system): None
Integrity (vulnerable system): Low
Availability (vulnerable system): None
Confidentiality (subsequent systems): None
Integrity (subsequent systems): None
Availability (subsequent systems): None
Exploit maturity: Unreported

Weakness

CWE-61: UNIX Symbolic Link (Symlink) Following

The product, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files.

How to prevent it

Implementation: Symbolic link attacks often occur when a program creates a tmp directory that stores files/links. Access to the directory should be restricted to the program as to prevent attackers from manipulating the files.
Architecture and Design: Follow the principle of least privilege when assigning access rights to entities in a software system. Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

References

Advisories

github.com/advisories/GHSA-xx64-wwv2-hcqq

Packages

Timeline

Apr 27, 2026 Published
Oct 12, 2026 Last updated by the source

Advisory	Severity	Why it's related
GHSA-3cv2-h65g-fgmm astral-tokio-tar has a PAX Header Desynchronization issue	Medium	Also affects astral-tokio-tar
GHSA-fp55-jw48-c537 astral-tokio-tar is Vulnerable to PAX Header Desynchronization	Medium	Also affects astral-tokio-tar
GHSA-6gx3-4362-rf54 astral-tokio-tar insufficiently validates PAX extensions during extraction	Medium	Also affects astral-tokio-tar
GHSA-j5gw-2vrg-8fgx astral-tokio-tar Vulnerable to PAX Header Desynchronization	High	Also affects astral-tokio-tar
GHSA-3wgq-wrwc-vqmv astral-tokio-tar has a path traversal in tar extraction	Medium	Also affects astral-tokio-tar
GHSA-hjqx-j4rw-g7xv zip: Arbitrary file write outside the extraction directory, because ZipArchive::extract validates symlink targets lexically.	High	Same weakness, CWE-61
GHSA-p8v3-89rh-jxc7 Nginx UI: Backup restore follows crafted symlinks into the live Nginx configuration path before restore flags are applied	High	Same weakness, CWE-61
GHSA-f794-5jv7-7672 NLTK: Downloader.download follows hardlinks and overwrites outside-root files	High	Same weakness, CWE-61

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