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[email protected]NVD:CVE-2021-3493

HistoryApr 17, 2021 - 5:15 a.m.

CVE-2021-3493

2021-04-1705:15:14

CWE-270

CWE-863

[email protected]

web.nvd.nist.gov

linux kernel

overlayfs

file capabilities

user namespaces

ubuntu

elevated privileges

CVSS2

7.2

Attack Vector

LOCAL

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

COMPLETE

Integrity Impact

COMPLETE

Availability Impact

COMPLETE

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

CVSS3

7.8

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

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

EPSS

0.008

Percentile

82.3%

JSON

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.

Affected configurations

Nvd

Node

canonicalubuntu_linuxRange<18.04lts

canonicalubuntu_linuxRange18.04.1–20.04lts

Node

canonicalubuntu_linuxRange<20.10-

VendorProductVersionCPE
canonicalubuntu_linux*cpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:lts:*:*:*
canonicalubuntu_linux*cpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:-:*:*:*