v3.21.3 Thu, Jul 9
Helm v3.21.2 is a patch release to correct bump the Kubernetes client libraries (client-go, etc) to match the expected Kubernetes v1.36 release. Users are encouraged to upgrade for the best experience.
Helm v3.21.0 is a feature release. Users are encouraged to upgrade for the best experience. > [!WARNING] > Helm v3 is approaching end-of-life. Please update to Helm v4.
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.
A Helm contributor discovered an improper validation of type error when parsing Chart.yaml and index.yaml files that can lead to a panic. ### Impact There are two areas of YAML validation that were impacted. First, when a `Chart.yaml` file had a `null` maintainer or the `child` or `parent` of a dependencies `import-values` could be parsed as something other than a string, `helm lint` would panic.
A Helm contributor discovered that it was possible to craft a JSON Schema file in a manner which could cause Helm to use all available memory and have an out of memory (OOM) termination. ### Impact A malicious chart can point `$ref` in _values.schema.json_ to a device (e.g. `/dev/*`) or other problem file which could cause Helm to use all available memory and have an out of memory (OOM) termination. ### Patches This issue has been resolved in Helm v3.18.5.
A Helm contributor discovered that a specially crafted `Chart.yaml` file along with a specially linked `Chart.lock` file can lead to local code execution when dependencies are updated. ### Impact Fields in a `Chart.yaml` file, that are carried over to a `Chart.lock` file when dependencies are updated and this file is written, can be crafted in a way that can cause execution if that same content were in a file that is executed (e.g., a `bash.rc` file or shell script).
A Helm contributor discovered that a specially crafted JSON Schema within a chart can lead to a stack overflow. ### Impact A JSON Schema file within a chart can be crafted with a deeply nested chain of references, leading to parser recursion that can exceed the stack size limit and trigger a stack overflow. ### Patches This issue has been resolved in Helm v3.17.3. ### Workarounds Ensure that the JSON Schema within any charts loaded by Helm does not have a large number of nested references.
A Helm contributor discovered that a specially crafted chart archive file can cause Helm to use all available memory and have an out of memory (OOM) termination. ### Impact A chart archive file can be crafted in a manner where it expands to be significantly larger uncompressed than compressed (e.g., >800x difference). When Helm loads this specially crafted chart, memory can be exhausted causing the application to terminate. ### Patches This issue has been resolved in Helm v3.17.3.
A Helm contributor discovered uninitialized variable vulnerability when Helm parses index and plugin yaml files missing expected content. ### Impact When either an `index.yaml` file or a plugins `plugin.yaml` file were missing all metadata a panic would occur in Helm. In the Helm SDK this is found when using the `LoadIndexFile` or `DownloadIndexFile` functions in the `repo` package or the `LoadDir` function in the `plugin` package.
A Helm contributor discovered a path traversal vulnerability when Helm saves a chart including at download time. ### Impact When either the Helm client or SDK is used to save a chart whose name within the `Chart.yaml` file includes a relative path change, the chart would be saved outside its expected directory based on the changes in the relative path. The validation and linting did not detect the path changes in the name. ### Patches This issue has been resolved in Helm v3.14.1.
A Helm contributor discovered an information disclosure vulnerability using the `getHostByName` template function. ### Impact `getHostByName` is a Helm template function introduced in Helm v3. The function is able to accept a hostname and return an IP address for that hostname. To get the IP address the function performs a DNS lookup. The DNS lookup happens when used with `helm install|upgrade|template` or when the Helm SDK is used to render a chart.
Fuzz testing, by Ada Logics and sponsored by the CNCF, identified input to functions in the `_chartutil_` package that can cause a segmentation violation. Applications that use functions from the `_chartutil_` package in the Helm SDK can have a Denial of Service attack when they use this package and it panics. ### Impact The `_chartutil_` package contains a parser that loads a JSON Schema validation file.
Fuzz testing, by Ada Logics and sponsored by the CNCF, identified input to functions in the `_repo_` package that can cause a segmentation violation. Applications that use functions from the `_repo_` package in the Helm SDK can have a Denial of Service attack when they use this package and it panics. ### Impact The `_repo_` package contains a handler that processes the index file of a repository. For example, the Helm client adds references to chart repositories where charts are managed.
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.
Fuzz testing, by Ada Logics and sponsored by the CNCF, identified input to functions in the `_strvals_` package that can cause an out of memory panic. Out of memory panics 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.
Since Helm 2 was released, a well-documented aspect of Helm is that the Helm chart's version number MUST follow the SemVer2 specification. In the past, Helm would not permit charts with malformed versions. At some point, a patch was merged that changed this - On a version parse error, the version number was simply passed along as-is. This provided a vector for malicious data to be injected into Helm and potentially used in various ways.
The Helm core maintainers have identified an information disclosure vulnerability in Helm 3.0.0-3.2.3. ### Impact A traversal attack is possible when installing Helm plugins from a tar archive over HTTP. It is possible for a malicious plugin author to inject a relative path into a plugin archive, and copy a file outside of the intended directory. Traversal Attacks are a form of a Directory Traversal that can be exploited by extracting files from an archive.
While working on the Helm source, a Helm core maintainer discovered a situation where the username and password credentials associated with a Helm repository could be passed on to another domain referenced by that Helm repository. ### Impact The `index.yaml` within a Helm chart repository contains a reference where to get the chart archive for each version of a chart. The reference can be relative to the `index.yaml` file or a URL to location.
The Helm core maintainers have identified a high severity security vulnerability in Go's `crypto` package affecting all versions prior to Helm 2.16.8 and Helm 3.1.0. Thanks to @ravin9249 for identifying the vulnerability. ### Impact Go before 1.12.16 and 1.13.x before 1.13.7 (and the `crypto/cryptobyte` package before 0.0.0-20200124225646-8b5121be2f68 for Go) allows attacks on clients resulting in a panic via a malformed X.509 certificate.
The Helm core maintainers have identified an information disclosure vulnerability in Helm 3.0.0-3.1.2. ### Impact `lookup` is a Helm template function introduced in Helm v3. It is able to lookup resources in the cluster to check for the existence of specific resources and get details about them. This can be used as part of the process to render templates. The documented behavior of `helm template` states that it does not attach to a remote cluster.
### Impact During a security audit of Helm's code base, Helm maintainers identified a bug in which a Helm plugin can contain duplicates of the same entry, with the last one always used. If a plugin is compromised, this lowers the level of access that an attacker needs to modify a plugin's install hooks, causing a local execution attack.
### Impact Security researchers at Trail of Bits discovered that plugin names are not sanitized properly. As a result, a malicious plugin author could use characters in a plugin name that would result in unexpected behavior, such as duplicating the name of another plugin or spoofing the output to `helm --help`. ### Specific Go Packages Affected helm.sh/helm/v3/pkg/plugin ### Patches This issue has been patched in Helm 3.3.2. ### Workarounds Do not install untrusted Helm plugins.
### Impact During a security audit of Helm's code base, security researchers at Trail of Bits identified a bug in which the a Helm repository can contain duplicates of the same chart, with the last one always used. If a repository is compromised, this lowers the level of access that an attacker needs to inject a bad chart into a repository. To perform this attack, an attacker must have write access to the index file (which can occur during a MITM attack on a non-SSL connection).
### Impact During a security audit of Helm's code base, security researchers at Trail of Bits identified a bug in which the `alias` field on a `Chart.yaml` is not properly sanitized. This could lead to the injection of unwanted information into a chart.