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From: Marc Deslauriers <marc.deslauriers@canonical.com>
Reply-To: Ubuntu Security <security@ubuntu.com>
To: "ubuntu-security-announce@lists.ubuntu.com"
 <ubuntu-security-announce@lists.ubuntu.com>
Message-ID: <ecb87f5b-031e-5f64-2aa2-d3bb7585df1f@canonical.com>
Subject: [USN-5100-1] containerd vulnerability

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==========================================================================
Ubuntu Security Notice USN-5100-1
October 04, 2021

containerd vulnerability
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 21.04
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

containerd would allow unintended access to files.

Software Description:
- containerd: daemon to control runC

Details:

It was discovered that containerd insufficiently restricted permissions on
container root and plugin directories. If a user or automated system were
tricked into launching a specially crafted container image, a remote
attacker could traverse directory contents and modify files and execute
programs on the host filesystem, possibly leading to privilege escalation.

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 21.04:
  containerd                      1.5.2-0ubuntu1~21.04.3

Ubuntu 20.04 LTS:
  containerd                      1.5.2-0ubuntu1~20.04.3

Ubuntu 18.04 LTS:
  containerd                      1.5.2-0ubuntu1~18.04.3

After a standard system update you need to restart containerd to make
all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-5100-1
  CVE-2021-41103

Package Information:
  https://launchpad.net/ubuntu/+source/containerd/1.5.2-0ubuntu1~21.04.3
  https://launchpad.net/ubuntu/+source/containerd/1.5.2-0ubuntu1~20.04.3
  https://launchpad.net/ubuntu/+source/containerd/1.5.2-0ubuntu1~18.04.3


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