CVE-2022-2503: Linux Kernel LoadPin bypass via dm-verity table reload

Description

Dm-verity is used for extending root-of-trust to root filesystems. LoadPin builds on this property to restrict module/firmware loads to just the trusted root filesystem. Device-mapper table reloads currently allow users with root privileges to switch out the target with an equivalent dm-linear target and bypass verification till reboot. This allows root to bypass LoadPin and can be used to load untrusted and unverified kernel modules and firmware, which implies arbitrary kernel execution and persistence for peripherals that do not verify firmware updates. We recommend upgrading past commit 4caae58406f8ceb741603eee460d79bacca9b1b5

CVSS vector

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

Attack vector

Local

Complexity

Low

Privileges

High

User interaction

None

Confidentiality

High

Integrity

High

Availability

High

Scope

Unchanged

Exploitation

Is it being used?

Exploit prediction (EPSS)0.4% · higher than 36% of CVEs

Exploited in the wildNo evidence yet

CISA KEVNot listed

Ransomware campaign useNot known

Affected products

Which versions

KE

Kernel · Linux

before 4caae58406f8ceb741603eee460d79bacca9b1b5 · source: vendor, NVD

SS

SIMATIC S7-1500 TM MFP - GNU/Linux subsystem · Siemens

before V1.1 · source: CISA