5.8 Medium
CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:M/Au:N/C:N/I:P/A:P
8.2 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
NONE
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
0.007 Low
EPSS
Percentile
80.2%
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.
3.2.3 || 4.4.15 || 5.0.7 || 6.1.2
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.
cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf
github.com/advisories/GHSA-r628-mhmh-qjhw
github.com/isaacs/node-tar/commit/46fe35083e2676e31c4e0a81639dce6da7aaa356
github.com/isaacs/node-tar/commit/5987d9a41f6bfbf1ddab1098e1fdcf1a5618f571
github.com/isaacs/node-tar/commit/85d3a942b4064e4ff171f91696fced7975167349
github.com/isaacs/node-tar/commit/9dbdeb6df8e9dbd96fa9e84341b9d74734be6c20
github.com/npm/node-tar/commit/9dbdeb6df8e9dbd96fa9e84341b9d74734be6c20
github.com/npm/node-tar/security/advisories/GHSA-r628-mhmh-qjhw
nvd.nist.gov/vuln/detail/CVE-2021-32803
www.npmjs.com/advisories/1771
www.npmjs.com/package/tar
www.oracle.com/security-alerts/cpuoct2021.html
5.8 Medium
CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:M/Au:N/C:N/I:P/A:P
8.2 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
NONE
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
0.007 Low
EPSS
Percentile
80.2%