Security Bulletin: IBM Cloud Kubernetes Service is affected by a containerd security vulnerability (CVE-2022-24769)

Summary

IBM Cloud Kubernetes Service is affected by a security vulnerability found in containerd where containers were incorrectly started with non-empty inheritable Linux process capabilities, creating an atypical Linux environment and enabling programs with inheritable file capabilities to elevate those capabilities to the permitted set during execve(2). Containers which use Linux users and groups to perform privilege separation inside the container are most directly impacted (CVE-2022-24769).

Vulnerability Details

CVEID: CVE-2022-24769
Description: Moby could allow a local attacker to gain elevated privileges on the system, caused by an issue with containers started incorrectly with non-empty inheritable Linux process capabilities. By executing specially-crafted programs, an attacker could exploit this vulnerability to gain elevated privileges.
CVSS Base Score: 5.9
CVSS Temporal Score: <https://exchange.xforce.ibmcloud.com/vulnerabilities/222517&gt; for more information
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L)

Affected Products and Versions

IBM Cloud Kubernetes Service 1.23-1.23.5_1524
IBM Cloud Kubernetes Service 1.22-1.22.8_1546
IBM Cloud Kubernetes Service 1.21-1.21.11_1554
IBM Cloud Kubernetes Service 1.5-1.20

Remediation/Fixes

Updates for IBM Cloud Kubernetes Service cluster worker nodes at version 1.21 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:

1.23.5_1526
1.22.8_1548
1.21.11_1556

Customers running IBM Cloud Kubernetes Service clusters at version 1.19 or 1.20 must upgrade to version 1.21. Please review the documentation before starting an upgrade since additional actions may be required.

Customers running IBM Cloud Kubernetes Service clusters at version 1.18 or earlier must create a new cluster and deploy their apps to the new cluster.

IBM Cloud Kubernetes Service versions 1.19 and earlier are no longer supported, and version 1.20 is deprecated. 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

Complete CVSS v3 Guide
On-line Calculator v3

Off

CVE-2022-24769: Default inheritable capabilities for linux container should be empty

Related Information

IBM Secure Engineering Web Portal
IBM Product Security Incident Response Blog

*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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