Ubuntu update for containerd

1) Incorrect default permissions

EUVDB-ID: #VU57038

Risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-41103

CWE-ID: CWE-276 - Incorrect Default Permissions

Exploit availability: No

Description

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

The vulnerability exists due to incorrect default permissions for container root directories and some plugins. When the UID of an unprivileged Linux user on the host collided with the file owner or group inside a container, the unprivileged Linux user on the host can discover, read, and modify those files.

Mitigation

Update the affected package containerd to the latest version.

Vulnerable software versions

Ubuntu: 18.04 - 21.04

containerd (Ubuntu package): before 1.5.2-0ubuntu1~18.04.3

CPE2.3

• cpe:2.3:o:canonical:ubuntu:18.04:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu:20.04:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu:21.04:*:*:*:*:*:*:*
• cpe:2.3:a:canonical:containerd_ubuntu_package:*:*:*:*:*:ubuntu:*:*

External links

https://ubuntu.com/security/notices/USN-5100-1

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.