Denial of service via schema file in helm.sh/helm/v3
Certain JSON schema validation files can cause a Helm Client to panic, leading to a possible denial of service. The chartutil package contains a parser that loads a JSON Schema validation file. For example, the Helm client when rendering a chart will validate its values with the schema file. The chartutil package parses the schema file and loads it into memory, but some schema files can cause array data structures to be created causing a memory violation. The Helm Client will panic with a schema file that causes a memory violation panic. Helm is not a long running service so the panic will not affect future uses of the Helm client.
02 / AFFECTED SOFTWARE
Affected packages
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
Certain JSON schema validation files can cause a Helm Client to panic, leading to a possible denial of service. The chartutil package contains a parser that loads a JSON Schema validation file. For example, the Helm client when rendering a chart will validate its values with the schema file. The chartutil package parses the schema file and loads it into memory, but some schema files can cause array data structures to be created causing a memory violation. The Helm Client will panic with a schema file that causes a memory violation panic. Helm is not a long running service so the panic will not affect future uses of the Helm client.
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. For example, the Helm client when rendering a chart will validate its values with the schema file. The `_chartutil_` package parses the schema file and loads it into structures Go can work with. Some schema files can cause array data structures to be created causing a memory violation. Applications that use the `_chartutil_` package in the Helm SDK to parse a schema file can suffer a Denial of Service when that input causes a panic that cannot be recovered from. The Helm Client will panic with a schema file that causes a memory violation panic. 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 schema files that are correctly formatted before passing them to the `_chartutil_` 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.
Helm is a tool for managing Charts, pre-configured Kubernetes resources. Versions prior to 3.10.3 are subject to NULL Pointer Dereference in the_chartutil_ package that can cause a segmentation violation. The _chartutil_ package contains a parser that loads a JSON Schema validation file. For example, the Helm client when rendering a chart will validate its values with the schema file. The _chartutil_ package parses the schema file and loads it into structures Go can work with. Some schema files can cause array data structures to be created causing a memory violation. Applications that use the _chartutil_ package in the Helm SDK to parse a schema file can suffer a Denial of Service when that input causes a panic that cannot be recovered from. Helm is not a long running service so the panic will not affect future uses of the Helm client. This issue has been patched in 3.10.3. SDK users can validate schema files that are correctly formatted before passing them to the _chartutil_ functions.
Helm is a tool for managing Charts, pre-configured Kubernetes resources. Versions prior to 3.10.3 are subject to NULL Pointer Dereference in the_chartutil_ package that can cause a segmentation violation. The _chartutil_ package contains a parser that loads a JSON Schema validation file. For example, the Helm client when rendering a chart will validate its values with the schema file. The _chartutil_ package parses the schema file and loads it into structures Go can work with. Some schema files can cause array data structures to be created causing a memory violation. Applications that use the _chartutil_ package in the Helm SDK to parse a schema file can suffer a Denial of Service when that input causes a panic that cannot be recovered from. Helm is not a long running service so the panic will not affect future uses of the Helm client. This issue has been patched in 3.10.3. SDK users can validate schema files that are correctly formatted before passing them to the _chartutil_ functions.
05 / REFERENCES
Further evidence
- https://github.com/helm/helm/commit/bafafa8bb1b571b61d7a9528da8d40c307dade3d
- https://github.com/helm/helm/security/advisories/GHSA-67fx-wx78-jx33
- https://github.com/helm/helm
- https://nvd.nist.gov/vuln/detail/CVE-2022-23526
- https://pkg.go.dev/vuln/GO-2022-1166
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/23xxx/CVE-2022-23526.json