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MEDIUM5.3

GHSA-6rx9-889q-vv2r

Helm vulnerable to denial of service through string value parsing

Quick fix

GHSA-6rx9-889q-vv2r — helm.sh/helm/v3: upgrade to the fixed version with the command below.

go get helm.sh/helm/v3@v3.10.3

Details

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](https://github.com/helm/community/blob/master/SECURITY.md) document.

### Credits

Disclosed by Ada Logics in a fuzzing audit sponsored by CNCF.

Are you affected?

Enter the version of the package you're using.

Affected packages

Go/helm.sh/helm/v3
Introduced in: 0Fixed in: 3.10.3
Fixgo get helm.sh/helm/v3@v3.10.3

References