Time of Check Time of Use (TOCTOU)
Affecting chownr package, versions <1.1.0
Report new vulnerabilities
Do your applications use this vulnerable package?
Test your applications
Overview
chownr is a package that takes the same arguments as fs.chown()
Affected versions of this package are vulnerable to Time of Check Time of Use (TOCTOU). Affected versions of this package are vulnerable toTime of Check Time of Use (TOCTOU) attacks.
It does not dereference symbolic links and changes the owner of the link, which can trick it into descending into unintended trees if a non-symlink is replaced by a symlink at a critical moment:
fs.lstat(pathChild, function(er, stats) {
if (er)
return cb(er)
if (!stats.isSymbolicLink())
chownr(pathChild, uid, gid, then)
Remediation
Upgrade chownr
to version 1.1.0 or higher.
References
CVSS Score
4.4
medium severity
-
Attack VectorLocal
-
Attack ComplexityLow
-
Privileges RequiredNone
-
User InteractionRequired
-
ScopeUnchanged
-
ConfidentialityNone
-
IntegrityLow
-
AvailabilityLow
- Credit
- Jeff Epler
- CVE
- CVE-2017-18869
- CWE
- CWE-264
- Snyk ID
- npm:chownr:20180731
- Disclosed
- 31 Jul, 2018
- Published
- 31 Jul, 2018