Headline
CVE-2022-23524: Denial of service through string value parsing
Helm is a tool for managing Charts, pre-configured Kubernetes resources. Versions prior to 3.10.3 are subject to Uncontrolled Resource Consumption, resulting in Denial of Service. Input to functions in the strvals package can cause a stack overflow. In Go, a stack overflow cannot be recovered from. Applications that use functions from the strvals package in the Helm SDK can have a Denial of Service attack when they use this package and it panics. This issue has been patched in 3.10.3. SDK users can validate strings supplied by users won’t create large arrays causing significant memory usage before passing them to the strvals functions.
Fuzz testing, by Ada Logics and sponsored by the CNCF, identified input to functions in the strvals package that can cause a stack overflow. In Go, a stack overflow cannot be recovered from. Applications that use functions from the strvals package in the Helm SDK can have a Denial of Service attack when they use this package and it panics.
Impact
The strvals package contains a parser that turns strings into Go structures. For example, the Helm client has command line flags like --set, --set-string, and others that enable the user to pass in strings that are merged into the values. The strvals package converts these strings into structures Go can work with. Some string inputs can cause array data structures to be created causing a stack overflow.
Applications that use the strvals package in the Helm SDK to parse user supplied input can suffer a Denial of Service when that input causes a panic that cannot be recovered from.
The Helm Client will panic with input to --set, --set-string, and other value setting flags that causes a stack overflow. Helm is not a long running service so the panic will not affect future uses of the Helm client.
Patches
This issue has been resolved in 3.10.3.
Workarounds
SDK users can validate strings supplied by users won’t create large arrays causing significant memory usage before passing them to the strvals functions.
For more information
Helm’s security policy is spelled out in detail in our SECURITY document.
Credits
Disclosed by Ada Logics in a fuzzing audit sponsored by CNCF.
Related news
Red Hat Security Advisory 2023-1646-01 - Red Hat OpenShift Container Platform is Red Hat's cloud computing Kubernetes application platform solution designed for on-premise or private cloud deployments. This advisory contains the RPM packages for Red Hat OpenShift Container Platform 4.12.11. Issues addressed include a denial of service vulnerability.
Red Hat OpenShift Container Platform release 4.12.11 is now available with updates to packages and images that fix several bugs and add enhancements. Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original. Related CVEs: * CVE-2022-23524: A flaw was found in Helm, a tool for managing Charts, a pre-configured Kubernetes resources. Versions prior to 3.10.3 are subject to Uncontrolled Resource Consumption. Input to functions in the _strvals_ package could cause a stack overflow that is unrecoverable by Go....
Fuzz testing, by Ada Logics and sponsored by the CNCF, identified input to functions in the _strvals_ package that can cause a stack overflow. In Go, a stack overflow cannot be recovered from. Applications that use functions from the _strvals_ package in the Helm SDK can have a Denial of Service attack when they use this package and it panics. ### Impact The _strvals_ package contains a parser that turns strings into Go structures. For example, the Helm client has command line flags like `--set`, `--set-string`, and others that enable the user to pass in strings that are merged into the values. The _strvals_ package converts these strings into structures Go can work with. Some string inputs can cause array data structures to be created causing a stack overflow. Applications that use the _strvals_ package in the Helm SDK to parse user supplied input can suffer a Denial of Service when that input causes a panic that cannot be recovered from. The Helm Client will panic with input to `...