CVE CyberSecurity Database News

CVE-2022-41939 The kub::func library and CLI enables development and deployment of Kubernetes functions.

Poster -

Function is a client library and CLI enabling the development and deployment of Kubernetes functions. Developers using a malicious or compromised third-party buildpack could expose their registry credentials or local docker socket to a malicious `lifecycle` container. This issues has been patched in PR #1442, and is part of release 1.8.1. This issue only affects users who are using function buildpacks from third-parties; pinning the builder image to a specific content-hash with a valid `lifecycle` image will also mitigate the attack. In addition to the security issues outlined above, there are a few minor known issues in the release: The function CLI does not work on Windows. It is recommended to use a cross-built Linux environment.
It is not possible to deploy functions using external custom domains.
Function 1.8.1 introduces a breaking change in the `args` field of the function definition. This is a breaking change for functions that have previously been created with the 1.8.0 version. If a function that was created in 1.8.0 is upgraded to 1.8.1, the `args` field must be updated with an appropriate value.

What is a buildpack?

A Kubernetes buildpack is a set of scripts which are deployed locally on the cluster and then executed to perform various tasks in order to transform an image into a set of container images.
The first step in using buildpacks is to create an account with a third-party builder, including ClusterHQ's buildpack. For example, you could use our CLDNS buildpack that builds Docker images for Node.js applications. Then, you'll need to add the third-party buildpack as one of your default ones so it is used when building containers in the cluster.

Function Security Vulnerability Summary

A vulnerability has been found in the `args` field of the function definition. A malicious buildpack could be used to expose registry credentials and local docker socket to a malicious `lifecycle` container.
This issue only affects users who are using function buildpacks from third-parties; pinning the builder image to a specific content-hash with a valid `lifecycle` image will also mitigate the attack.
In addition to the security issues outlined above, there are a few minor known issues in this release: The function CLI does not work on Windows. It is recommended to use a cross-built Linux environment. It is not possible to deploy functions using external custom domains. Function 1.8.1 introduces a breaking change in the `args` field of the function definition. This is a breaking change for functions that have previously been created with the 1.8.0 version. If a function that was created in 1.8.0 is upgraded to 1.8.1, the `args` field must be updated with an appropriate value

Function Security Improvements

The release also includes security and usability improvements, including:
**PR 1442**
Function 1.8.1 includes a fix for CVE-2019-19739 (private registry keys exposed in `lifecycle` container) as well as the following additional fixes:
* Reduce the risk of code injection vulnerability by allowing override of function context to be set with environment variables.
* Improve diagnostics for failures deploying functions to Kubernetes clusters by adding an informative message indicating that a user needs to create an account on GitHub.

Timeline

Published on: 11/19/2022 01:15:00 UTC
Last modified on: 11/26/2022 03:21:00 UTC

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