CVE-2021-3493

Description


The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities on files in an underlying file system. Due to the combination of unprivileged user namespaces along with a patch carried in the Ubuntu kernel to allow unprivileged overlay mounts, an attacker could use this to gain elevated privileges.

CvssV3 impact


BaseSeverity

HIGH

ConfidentialityImpact

HIGH

AttackComplexity

LOW

Scope

UNCHANGED

AttackVector

LOCAL

AvailabilityImpact

HIGH

IntegrityImpact

HIGH

PrivilegesRequired

LOW

BaseScore

7.8

VectorString

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Version

3.1

UserInteraction

NONE

CvssV2 impact


AccessComplexity

LOW

ConfidentialityImpact

COMPLETE

AvailabilityImpact

COMPLETE

IntegrityImpact

COMPLETE

BaseScore

7.2

VectorString

AV:L/AC:L/Au:N/C:C/I:C/A:C

Version

2.0

AccessVector

LOCAL

Authentication

NONE