Security Bulletin
Summary
IBM Cloud Kubernetes Service is affected by a security vulnerability found in containerd's CRI implementation where a user can exhaust memory on the host. (CVE-2022-23471).
Vulnerability Details
CVEID: CVE-2022-23471
Description: containerd is an open source container runtime. A bug was found in containerd's CRI implementation where a user can exhaust memory on the host. In the CRI stream server, a goroutine is launched to handle terminal resize events if a TTY is requested. If the user's process fails to launch due to, for example, a faulty command, the goroutine will be stuck waiting to send without a receiver, resulting in a memory leak. Kubernetes and crictl can both be configured to use containerd's CRI implementation and the stream server is used for handling container IO. This bug has been fixed in containerd 1.6.12 and 1.5.16. Users should update to these versions to resolve the issue. Users unable to upgrade should ensure that only trusted images and commands are used and that only trusted users have permissions to execute commands in running containers.
CVSS Base Score: 5.7
CVSS Temporal Score: https://exchange.xforce.ibmcloud.com/vulnerabilities/241615 for more information
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H)
Affected Products and Versions
IBM Cloud Kubernetes Service 1.24-1.24.8_1546
IBM Cloud Kubernetes Service 1.23-1.23.14_1554
IBM Cloud Kubernetes Service 1.22-1.22.16_1580
IBM Cloud Kubernetes Service 1.5-1.21
Remediation/Fixes
Updates for IBM Cloud Kubernetes Service cluster worker nodes at version 1.22 or later are available that fix this vulnerability. Customers must update worker nodes created before the fix was available to address the vulnerability. See updating worker nodes for details on updating worker nodes. To verify your cluster worker nodes have been updated, use the following IBM Cloud CLI command to confirm the currently running versions:
ibmcloud ks workers --cluster <cluster name or ID>
If the versions are at one of the following patch levels or later, the cluster worker nodes have the fix:
1.25.5_1526
1.24.9_1548
1.23.15_1556
1.22.17_1583
Customers running IBM Cloud Kubernetes Service clusters at version 1.21 must upgrade to version 1.22. Please review the documentation before starting an upgrade since additional actions may be required.
Customers running IBM Cloud Kubernetes Service clusters at version 1.20 or earlier must create a new cluster and deploy their apps to the new cluster.
IBM Cloud Kubernetes Service versions 1.21 and earlier are no longer supported. See the IBM Cloud Kubernetes Service version information and update actions documentation for more information about Kubernetes versions and version support policies.
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References
*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.
Disclaimer
Review the IBM security bulletin disclaimer and definitions regarding your responsibilities for assessing potential impact of security vulnerabilities to your environment.
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Document Information
Modified date:
03 January 2023
UID
ibm16850799