GHSA-hr2v-4r36-88hr

Helm Chart extraction output directory collapse via `Chart.yaml` name dot-segment

Helm is a package manager for Charts for Kubernetes. In Helm versions <=3.20.1 and <=4.1.3, a specially crafted Chart will cause `helm pull --untar [chart URL | repo/chartname]` to write the Chart's contents to the immediate output directory (as defaulted to the current working directory; or as given by the `--destination` and `--untardir` flags), rather than the expected output directory suffixed by the chart's name. ### Impact The bug enables writing the Chart's contents (unpackaged/untar'ed) to the output directory `<output dir>/`, instead of the expected `<output dir>/<chart name>/`, potentially overwriting the contents of the targeted directory. Note: a chart name containing POSIX dot-dot, or dot-dot and slashes (as if to refer to parent directories) do not resolve beyond the output directory as designed. ### Patches This issue has been resolved in Helm v3.20.2 and v4.1.3 A Chart with an unexpected name (those specified to be "." or ".."), or a Chart name which results in a non-unique directory will be rejected. ### Workarounds Ensure the the name of the Chart does not comprise/contain POSIX pathname special directory references ie. dot-dot ("..") or dot ("."). In addition, ensuring that the `pull --untar` flag (or equivalent SDK option) refers to a unique/empty output directory prevents chart extraction from inadvertently overwriting existing files within the specified directory. ### Credits Oleh Konko @1seal