title: Ubuntu linux kernel shiftfs file system double free vulnerability
description: Shiftfs, an out-of-tree stacking file system included in Ubuntu Linux kernels, did not properly handle faults occurring during copy_from_user() correctly. These could lead to either a double-free situation or memory not being freed at all. An attacker could use this to cause a denial of service (kernel memory exhaustion) or gain privileges via executing arbitrary code. AKA ZDI-CAN-13562.
problem types: CWE-415: Double Free
affected:
{
product: Linux kernel
vendor: Ubuntu
versions:
lessThan: 5.8.0-50.56, status: affected, version: 5.8 kernel, versionType: custom
lessThan: 5.4.0-72.80 , status: affected, version: 5.4 kernel, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: LOCAL
availabilityImpact: HIGH
baseScore: 8.8
baseSeverity: HIGH
confidentialityImpact: HIGH
integrityImpact: HIGH
privilegesRequired: LOW
scope: CHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
version: 3.1
]