SB2020031004 - Ubuntu update for runC



SB2020031004 - Ubuntu update for runC

Published: March 10, 2020

Security Bulletin ID SB2020031004
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Local access
Highest impact Data manipulation

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 vulnerabilities.


1) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2019-16884)

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


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

The vulnerability exists due to incorrect checking of the mount targets in libcontainer/rootfs_linux.go in runc. A local user can bypass AppArmor restrictions and perform unauthorized actions on the system, as demonstrated by overwriting the /proc directory with a malicious Doker image.


2) Improper access control (CVE-ID: CVE-2019-19921)

CWE-ID: CWE-284 - Improper Access Control

CVSSv4: 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:P/U:Clear


The vulnerability allows a local user to gain unauthorized access to sensitive information.

The vulnerability exists due to improper access restrictions, related to libcontainer/rootfs_linux.go in runc. A local user with ability to spawn two containers with custom volume-mount configurations, and run custom images can escalate privileges on the system.


Remediation

Install update from vendor's website.