Security Bulletin
Summary
IBM Cloud Kubernetes Service is affected by a security vulnerability found in containerd that allows clients to misinterpret manifest and layer fields. If a `Content-Type` header changed between two pulls of the same digest, a client may interpret the resulting content differently. (CVE-2021-41190)
Vulnerability Details
CVEID: CVE-2021-41190
Description: Open Container Initiative Distribution Specification could allow a remote authenticated attacker to bypass security restrictions, caused by a flaw when a Content-Type header changed between two pulls of the same digest. By sending a specially-crafted request, an attacker could exploit this vulnerability to cause a client to interpret the resulting content differently.
CVSS Base Score: 3.0
CVSS Temporal Score: https://exchange.xforce.ibmcloud.com/vulnerabilities/213802 for more information
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:L/A:N)
Affected Products and Versions
IBM Cloud Kubernetes Service 1.21.0-1.21.6_1540
IBM Cloud Kubernetes Service 1.20.0-1.20.12_1562
IBM Cloud Kubernetes Service 1.19.0-1.19.16_1569
IBM Cloud Kubernetes Service 1.5-1.18
Remediation/Fixes
Updates for IBM Cloud Kubernetes Service cluster worker nodes at versions 1.19 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:
1.22.4_1532
1.21.7_1542
1.20.13_1564
1.19.16_1571
Customers running IBM Cloud Kubernetes Service clusters at version 1.18 must upgrade to version 1.19. Please review the documentation before starting an upgrade since additional actions may be required.
Customers running IBM Cloud Kubernetes Service clusters at version 1.17 or earlier must create a new cluster and deploy their apps to the new cluster.
IBM Cloud Kubernetes Service versions 1.18 and earlier are no longer supported, and version 1.19 is deprecated. See the IBM Cloud Kubernetes Service version information and update actions documentation for more information about Kubernetes versions and version support policies.
Monitor IBM Cloud Status for Future Security Bulletins
Monitor the security notifications on the IBM Cloud Status page to be advised of future security bulletins.
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.
Was this topic helpful?
Document Information
Modified date:
14 December 2021
UID
ibm16524974