Permissions, Privileges, and Access Controls in Linux kernel - CVE-2022-2503

 

Permissions, Privileges, and Access Controls in Linux kernel - CVE-2022-2503

Published: August 29, 2022


Vulnerability identifier: #VU66810
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2022-2503
CWE-ID: CWE-264
Exploitation vector: Local access
Exploit availability: No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel

Detailed vulnerability description

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.


How to mitigate CVE-2022-2503

Install updates from vendor's website.

Sources