Arbitrary File Creation/Overwrite via insufficient symlink protection due to directory cache poisoning #43

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2023-11-01T04:47:31Z

argoyle commented

2023-11-01 04:47:31 +00:00

(Migrated from gitlab.com)

⚠️ dependabot-gitlab has detected security vulnerability for tar in path: /, manifest_file: /package.json but was unable to update it! ⚠️

https://github.com/advisories/GHSA-r628-mhmh-qjhw

Package	Severity	Affected versions	Patched versions	IDs
tar (NPM)	HIGH	< 3.2.3	3.2.3	`GHSA-r628-mhmh-qjhw`,`CVE-2021-32803`

Description

Impact

Arbitrary File Creation, Arbitrary File Overwrite, Arbitrary Code Execution

node-tar aims to guarantee that any file whose location would be modified by a symbolic link is not extracted. This is, in part, achieved by ensuring that extracted directories are not symlinks. Additionally, in order to prevent unnecessary stat calls to determine whether a given path is a directory, paths are cached when directories are created.

This logic was insufficient when extracting tar files that contained both a directory and a symlink with the same name as the directory. This order of operations resulted in the directory being created and added to the node-tar directory cache. When a directory is present in the directory cache, subsequent calls to mkdir for that directory are skipped. However, this is also where node-tar checks for symlinks occur.

By first creating a directory, and then replacing that directory with a symlink, it was thus possible to bypass node-tar symlink checks on directories, essentially allowing an untrusted tar file to symlink into an arbitrary location and subsequently extracting arbitrary files into that location, thus allowing arbitrary file creation and overwrite.

This issue was addressed in releases 3.2.3, 4.4.15, 5.0.7 and 6.1.2.

Patches

3.2.3 || 4.4.15 || 5.0.7 || 6.1.2

Workarounds

Users may work around this vulnerability without upgrading by creating a custom filter method which prevents the extraction of symbolic links.

const tar = require('tar')

tar.x({
  file: 'archive.tgz',
  filter: (file, entry) => {
    if (entry.type === 'SymbolicLink') {
      return false
    } else {
      return true
    }
  }
})

Users are encouraged to upgrade to the latest patch versions, rather than attempt to sanitize tar input themselves.

References

⚠️ `dependabot-gitlab` has detected security vulnerability for `tar` in path: `/`, manifest_file: `/package.json` but was unable to update it! ⚠️ * https://github.com/advisories/GHSA-r628-mhmh-qjhw | Package | Severity | Affected versions | Patched versions | IDs | |-----------|----------|-------------------|------------------|----------------------------------------| | tar (NPM) | HIGH | < 3.2.3 | 3.2.3 | `GHSA-r628-mhmh-qjhw`,`CVE-2021-32803` | # Description ### Impact Arbitrary File Creation, Arbitrary File Overwrite, Arbitrary Code Execution `node-tar` aims to guarantee that any file whose location would be modified by a symbolic link is not extracted. This is, in part, achieved by ensuring that extracted directories are not symlinks. Additionally, in order to prevent unnecessary `stat` calls to determine whether a given path is a directory, paths are cached when directories are created. This logic was insufficient when extracting tar files that contained both a directory and a symlink with the same name as the directory. This order of operations resulted in the directory being created and added to the `node-tar` directory cache. When a directory is present in the directory cache, subsequent calls to mkdir for that directory are skipped. However, this is also where `node-tar` checks for symlinks occur. By first creating a directory, and then replacing that directory with a symlink, it was thus possible to bypass `node-tar` symlink checks on directories, essentially allowing an untrusted tar file to symlink into an arbitrary location and subsequently extracting arbitrary files into that location, thus allowing arbitrary file creation and overwrite. This issue was addressed in releases 3.2.3, 4.4.15, 5.0.7 and 6.1.2. ### Patches 3.2.3 || 4.4.15 || 5.0.7 || 6.1.2 ### Workarounds Users may work around this vulnerability without upgrading by creating a custom `filter` method which prevents the extraction of symbolic links. ```js const tar = require('tar') tar.x({ file: 'archive.tgz', filter: (file, entry) => { if (entry.type === 'SymbolicLink') { return false } else { return true } } }) ``` Users are encouraged to upgrade to the latest patch versions, rather than attempt to sanitize tar input themselves. # References * https://github.com/npm/node-tar/security/advisories/GHSA-r628-mhmh-qjhw * https://github.com/npm/node-tar/commit/9dbdeb6df8e9dbd96fa9e84341b9d74734be6c20 * https://www.npmjs.com/advisories/1771 * https://nvd.nist.gov/vuln/detail/CVE-2021-32803 * https://www.npmjs.com/package/tar * https://www.oracle.com/security-alerts/cpuoct2021.html * https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf * https://github.com/isaacs/node-tar/commit/46fe35083e2676e31c4e0a81639dce6da7aaa356 * https://github.com/isaacs/node-tar/commit/5987d9a41f6bfbf1ddab1098e1fdcf1a5618f571 * https://github.com/isaacs/node-tar/commit/85d3a942b4064e4ff171f91696fced7975167349 * https://github.com/isaacs/node-tar/commit/9dbdeb6df8e9dbd96fa9e84341b9d74734be6c20 * https://github.com/advisories/GHSA-r628-mhmh-qjhw

argoyle (Migrated from gitlab.com) closed this issue

2024-02-06 04:41:11 +00:00

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Reference: dancefinder/dancefinder-app#43