title: Malicious directory junction can cause WiX RemoveFoldersEx to possibly delete elevated files
description: WiX toolset lets developers create installers for Windows Installer, the Windows installation engine. The custom action behind WiX's `RemoveFolderEx` functionality could allow a standard user to delete protected directories. `RemoveFolderEx` deletes an entire directory tree during installation or uninstallation. It does so by recursing every subdirectory starting at a specified directory and adding each subdirectory to the list of directories Windows Installer should delete. If the setup author instructed `RemoveFolderEx` to delete a per-user folder from a per-machine installer, an attacker could create a directory junction in that per-user folder pointing to a per-machine, protected directory. Windows Installer, when executing the per-machine installer after approval by an administrator, would delete the target of the directory junction. This vulnerability is fixed in 3.14.1 and 4.0.5.
problem types: CWE-59: Improper Link Resolution Before File Access ('Link Following')
affected:
{
vendor: wixtoolset
product: issues
versions:
version: < 3.14.1, status: affected
version: >= 4.0.0, < 4.0.5, status: affected
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: LOCAL
availabilityImpact: HIGH
baseScore: 7.8
baseSeverity: HIGH
confidentialityImpact: NONE
integrityImpact: HIGH
privilegesRequired: LOW
scope: CHANGED
userInteraction: REQUIRED
vectorString: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:N/I:H/A:H
version: 3.1
]