CVE Vulnerabilities

CVE-2020-8539

Incorrect Default Permissions

Published: Dec 01, 2020 | Modified: Dec 08, 2020
CVSS 3.x
7.8
HIGH
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
4.6 MEDIUM
AV:L/AC:L/Au:N/C:P/I:P/A:P
RedHat/V2
RedHat/V3
Ubuntu

Kia Motors Head Unit with Software version: SOP.003.30.18.0703, SOP.005.7.181019, and SOP.007.1.191209 may allow an attacker to inject unauthorized commands, by executing the micomd executable deamon, to trigger unintended functionalities. In addition, this executable may be used by an attacker to inject commands to generate CAN frames that are sent into the M-CAN bus (Multimedia CAN bus) of the vehicle.

Weakness

During installation, installed file permissions are set to allow anyone to modify those files.

Affected Software

Name Vendor Start Version End Version
Head_unit_firmware Kia sop.003.30.18.0703 (including) sop.003.30.18.0703 (including)
Head_unit_firmware Kia sop.005.7.181019 (including) sop.005.7.181019 (including)
Head_unit_firmware Kia sop.007.1.191209 (including) sop.007.1.191209 (including)

Potential Mitigations

  • Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
  • Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

References