SB2022082921 - LoadPin bypass via dm-verity table reload in Linux kernel

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Main Vulnerability Database SB2022082921

SB2022082921 - LoadPin bypass via dm-verity table reload in Linux kernel

Published: August 29, 2022

Security Bulletin ID SB2022082921
Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Code execution

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 security vulnerability.


1) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2022-2503)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to the way dm-verity is used to restrict module/firmware loads to trusted root filesystem in LoadPin builds. 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.


Remediation

Install update from vendor's website.

References