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Security Bulletin: IBM Cloud Private is vulnerable to Kubernetes vulnerabilities (CVE-2020-8557, CVE-2020-8559)

Security Bulletin


IBM Cloud Private is vulnerable to Kubernetes vulnerabilities

Vulnerability Details

CVEID:   CVE-2020-8557
DESCRIPTION:   Kubernetes kubelet is vulnerable to a denial of service, caused by an issue with not including the /etc/hostsfile file by the kubelet eviction manager when calculating ephemeral storage usage. By writing a large amount of data to the /etc/hostsfile, a local authenticated attacker could exploit this vulnerability to fill the storage space of the node and cause the node to fail.
CVSS Base score: 5.5
CVSS Temporal Score: See: for the current score.
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)

CVEID:   CVE-2020-8559
DESCRIPTION:   Kubernetes kube-apiserver could allow a remote authenticated attacker to gain elevated privileges on the system, caused by a flaw when multiple clusters share the same certificate authority trusted by the client. By intercepting certain requests and sending a redirect response, an attacker could exploit this vulnerability to compromise other nodes.
CVSS Base score: 6.4
CVSS Temporal Score: See: for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:H)

Affected Products and Versions

Affected Product(s)Version(s)
IBM Cloud Private3.2.1 CD
IBM Cloud Private3.2.2 CD


Product defect fixes and security updates are only available for the two most recent Continuous Delivery (CD) update packages

  • IBM Cloud Private 3.2.1
  • IBM Cloud Private 3.2.2


For IBM Cloud Private 3.2.1, the defect fixes for Kubernetes require an update to the Kubernetes version. The ICP 3.2.2 fixpack updates Kubernetes from version 1.13.12 to 1.16.13 and includes defect fixes. The procedure is to first upgrade an ICP 3.2.1 deployment to ICP or newer. Then, you can apply the fix pack.


For IBM Cloud Private 3.2.2, apply Aug fix pack:


For IBM Cloud Private 3.1.0, 3.1.1, 3.1.2, 3.2.0:

  • Upgrade to the latest Continuous Delivery (CD) update package, IBM Cloud Private 
  • If required, individual product fixes can be made available between CD update packages for resolution of problems. Contact IBM support for assistance

Workarounds and Mitigations


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Change History

28 Sep 2020: Initial Publication

*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.


According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES ""AS IS"" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY.

Document Location


[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSBS6K","label":"IBM Cloud Private"},"Component":"","Platform":[{"code":"PF016","label":"Linux"}],"Version":"all","Edition":"","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
28 September 2020