Security Bulletin: IBM InfoSphere Information Server is affected by an information disclosure vulnerability in Kubernetes (CVE-2021-25740)

Summary

An information disclosure vulnerability in Kubernetes used by IBM InfoSphere Information Server was addressed.

Vulnerability Details

CVEID:CVE-2021-25740
**DESCRIPTION:**Kubernetes could allow a remote authenticated attacker to obtain sensitive information, caused by a confused deputy attack. By sending a specially-crafted request to create or edit Endpoints or EndpointSlices in the Kubernetes API, an attacker could exploit this vulnerability to obtain backend IPs information, and use this information to launch further attacks against the affected system.
CVSS Base score: 3.1
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/205570 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N)

Affected Products and Versions

Note: New suite installations of Information Server 11.7.1.4 are not vulnerable but installations upgraded to 11.7.1.4 may be vulnerable.

Remediation/Fixes

None

Workarounds and Mitigations

You can check whether your installation is affected by running the following command:

$ if kubectl get clusterrole system:aggregate-to-edit -oyaml | grep -q endpoints; then echo 'Affected'; else echo 'Not affected'; fi

Run the following commands to apply the fix:

    $ kubectl get clusterrole system:aggregate-to-edit -oyaml > /tmp/aggregate-to-edit-role.bak


    $ sed '/endpoints/d' /tmp/aggregate-to-edit-role.bak | kubectl replace -f -

The commands need only be applied once; the effect is not affected when subsequent patches are installed.