SB2021081073 - Ubuntu update for runc

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Main Vulnerability Database SB2021081073

SB2021081073 - Ubuntu update for runc

Published: August 10, 2021 Updated: October 31, 2026

Security Bulletin ID SB2021081073
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Adjecent network
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: 6.9 [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]


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) Security features bypass (CVE-ID: CVE-2021-30465)

CWE-ID: CWE-254 - Security Features

CVSSv4: 7 [CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to the security features bypass issue. A remote authenticated attacker on the local network can perform a symlink exchange attack and host filesystem being bind-mounted into the container.


Remediation

Install update from vendor's website.

References