Detections
Analytics
Alpine: tar: security update to 0
high Tenable Cloud Security Plugin ID 407317
Description
There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:- The npm package "tar" (aka node-tar) before versions 6.1.2, 5.0.7, 4.4.15, and 3.2.3 has an arbitrary File
Creation/Overwrite vulnerability via insufficient symlink protection. `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. (CVE-2021-32803)
- The npm package "tar" (aka node-tar) before versions 6.1.1, 5.0.6, 4.4.14, and 3.3.2 has a arbitrary File
Creation/Overwrite vulnerability due to insufficient absolute path sanitization. node-tar aims to prevent
extraction of absolute file paths by turning absolute paths into relative paths when the `preservePaths`
flag is not set to `true`. This is achieved by stripping the absolute path root from any absolute file
paths contained in a tar file. For example `/home/user/.bashrc` would turn into `home/user/.bashrc`. This
logic was insufficient when file paths contained repeated path roots such as `////home/user/.bashrc`.
`node-tar` would only strip a single path root from such paths. When given an absolute file path with
repeating path roots, the resulting path (e.g. `///home/user/.bashrc`) would still resolve to an absolute
path, thus allowing arbitrary file creation and overwrite. This issue was addressed in releases 3.2.2,
4.4.14, 5.0.6 and 6.1.1. Users may work around this vulnerability without upgrading by creating a custom
`onentry` method which sanitizes the `entry.path` or a `filter` method which removes entries with absolute
paths. See referenced GitHub Advisory for details. Be aware of CVE-2021-32803 which fixes a similar bug in
later versions of tar. (CVE-2021-32804)
- The npm package "tar" (aka node-tar) before versions 4.4.16, 5.0.8, and 6.1.7 has an arbitrary file
creation/overwrite and arbitrary code execution vulnerability. 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, where the symlink and directory names in the archive entry used
backslashes as a path separator on posix systems. The cache checking logic used both `\` and `/`
characters as path separators, however `\` is a valid filename character on posix systems. 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. Additionally, a similar confusion could arise on case-insensitive
filesystems. If a tar archive contained a directory at `FOO`, followed by a symbolic link named `foo`,
then on case-insensitive file systems, the creation of the symbolic link would remove the directory from
the filesystem, but _not_ from the internal directory cache, as it would not be treated as a cache hit. A
subsequent file entry within the `FOO` directory would then be placed in the target of the symbolic link,
thinking that the directory had already been created. These issues were addressed in releases 4.4.16,
5.0.8 and 6.1.7. The v3 branch of node-tar has been deprecated and did not receive patches for these
issues. If you are still using a v3 release we recommend you update to a more recent version of node-tar.
If this is not possible, a workaround is available in the referenced GHSA-9r2w-394v-53qc. (CVE-2021-37701)
See Also
https://security.alpinelinux.org/vuln/CVE-2021-32803
Plugin Details
Severity: High
ID: 407317
Version: Revision 1.37
Type: Local
Published: 10/31/2023
Updated: 7/10/2026
Supported Sensors: Agentless Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security
Risk Information
VPR
Risk Factor: Medium
Score: 6.3
Percentile: 96.77
CVSS v2
Risk Factor: Medium
Base Score: 5.8
Temporal Score: 4.3
Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:P
CVSS Score Source: CVE-2021-32804
CVSS v3
Risk Factor: High
Base Score: 8.6
Temporal Score: 7.5
Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
CVSS Score Source: CVE-2021-37701
Vulnerability Information
Exploit Ease: No known exploits are available
Vulnerability Publication Date: 8/3/2021