Duplicated chart entries in Helm
Description
In Helm before versions 2.16.11 and 3.3.2, 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). This issue has been patched in Helm 3.3.2 and 2.16.11. A possible workaround is to manually review the index file in the Helm repository cache before installing software.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
helm.sh/helm/v3Go | >= 3.0.0, < 3.3.2 | 3.3.2 |
helm.sh/helmGo | < 2.16.11 | 2.16.11 |
Affected products
1Patches
2055dd41cbe53Merge pull request from GHSA-jm56-5h66-w453
3 files changed · +48 −2
pkg/downloader/chart_downloader_test.go+1 −1 modified@@ -71,7 +71,7 @@ func TestResolveChartRef(t *testing.T) { if tt.fail { continue } - t.Errorf("%s: failed with error %s", tt.name, err) + t.Errorf("%s: failed with error %q", tt.name, err) continue } if got := u.String(); got != tt.expect {
pkg/repo/index.go+18 −1 modified@@ -228,6 +228,23 @@ type ChartVersion struct { Created time.Time `json:"created,omitempty"` Removed bool `json:"removed,omitempty"` Digest string `json:"digest,omitempty"` + + // ChecksumDeprecated is deprecated in Helm 3, and therefore ignored. Helm 3 replaced + // this with Digest. However, with a strict YAML parser enabled, a field must be + // present on the struct for backwards compatibility. + ChecksumDeprecated string `json:"checksum,omitempty"` + + // EngineDeprecated is deprecated in Helm 3, and therefore ignored. However, with a strict + // YAML parser enabled, this field must be present. + EngineDeprecated string `json:"engine,omitempty"` + + // TillerVersionDeprecated is deprecated in Helm 3, and therefore ignored. However, with a strict + // YAML parser enabled, this field must be present. + TillerVersionDeprecated string `json:"tillerVersion,omitempty"` + + // URLDeprecated is deprectaed in Helm 3, superseded by URLs. It is ignored. However, + // with a strict YAML parser enabled, this must be present on the struct. + URLDeprecated string `json:"url,omitempty"` } // IndexDirectory reads a (flat) directory and generates an index. @@ -281,7 +298,7 @@ func IndexDirectory(dir, baseURL string) (*IndexFile, error) { // This will fail if API Version is not set (ErrNoAPIVersion) or if the unmarshal fails. func loadIndex(data []byte) (*IndexFile, error) { i := &IndexFile{} - if err := yaml.Unmarshal(data, i); err != nil { + if err := yaml.UnmarshalStrict(data, i); err != nil { return i, err } i.SortEntries()
pkg/repo/index_test.go+29 −0 modified@@ -95,6 +95,35 @@ func TestLoadIndex(t *testing.T) { verifyLocalIndex(t, i) } +const indexWithDuplicates = ` +apiVersion: v1 +entries: + nginx: + - urls: + - https://kubernetes-charts.storage.googleapis.com/nginx-0.2.0.tgz + name: nginx + description: string + version: 0.2.0 + home: https://github.com/something/else + digest: "sha256:1234567890abcdef" + nginx: + - urls: + - https://kubernetes-charts.storage.googleapis.com/alpine-1.0.0.tgz + - http://storage2.googleapis.com/kubernetes-charts/alpine-1.0.0.tgz + name: alpine + description: string + version: 1.0.0 + home: https://github.com/something + digest: "sha256:1234567890abcdef" +` + +// TestLoadIndex_Duplicates is a regression to make sure that we don't non-deterministically allow duplicate packages. +func TestLoadIndex_Duplicates(t *testing.T) { + if _, err := loadIndex([]byte(indexWithDuplicates)); err == nil { + t.Errorf("Expected an error when duplicate entries are present") + } +} + func TestLoadIndexFile(t *testing.T) { i, err := LoadIndexFile(testfile) if err != nil {
8 files changed · +109 −0
pkg/chartutil/requirements.go+13 −0 modified@@ -17,7 +17,9 @@ package chartutil import ( "errors" + "fmt" "log" + "regexp" "strings" "time" @@ -219,6 +221,9 @@ func ProcessRequirementsTags(reqs *Requirements, cvals Values) { } +// Validate alias names against this regexp +var aliasRegexp = regexp.MustCompile("^[a-zA-Z0-9-_]+$") + func getAliasDependency(charts []*chart.Chart, aliasChart *Dependency) *chart.Chart { var chartFound chart.Chart for _, existingChart := range charts { @@ -237,6 +242,11 @@ func getAliasDependency(charts []*chart.Chart, aliasChart *Dependency) *chart.Ch chartFound = *existingChart newMetadata := *existingChart.Metadata if aliasChart.Alias != "" { + // Make sure Alias is well-formed + if !aliasRegexp.MatchString(aliasChart.Alias) { + fmt.Printf("Invalid alias in dependency %q. Skipping.", aliasChart.Name) + continue + } newMetadata.Name = aliasChart.Alias } chartFound.Metadata = &newMetadata @@ -286,6 +296,9 @@ func doProcessRequirementsEnabled(c *chart.Chart, v *chart.Config, path string) chartDependencies = append(chartDependencies, chartDependency) } if req.Alias != "" { + if !aliasRegexp.MatchString(req.Alias) { + return fmt.Errorf("illegal alias name in %q", req.Name) + } req.Name = req.Alias } }
pkg/chartutil/requirements_test.go+21 −0 modified@@ -370,11 +370,19 @@ func TestGetAliasDependency(t *testing.T) { } // Failure case + resetName := req.Dependencies[0].Name req.Dependencies[0].Name = "something-else" if aliasChart := getAliasDependency(c.Dependencies, req.Dependencies[0]); aliasChart != nil { t.Fatalf("expected no chart but got %s", aliasChart.Metadata.Name) } + // Add a bad alias name + req.Dependencies[0].Name = resetName + req.Dependencies[0].Alias = "$foobar" + if aliasChart := getAliasDependency(c.Dependencies, req.Dependencies[0]); aliasChart != nil { + t.Fatalf("expected no chart but got %s", aliasChart.Metadata.Name) + } + req.Dependencies[0].Version = "something else which is not in the compatible range" if version.IsCompatibleRange(req.Dependencies[0].Version, aliasChart.Metadata.Version) { t.Fatalf("Dependency chart version which is not in the compatible range should cause a failure other than a success ") @@ -516,3 +524,16 @@ func TestDependentChartsWithSomeSubchartsSpecifiedInRequirements(t *testing.T) { } } + +func TestAliasRegexp(t *testing.T) { + for name, shouldPass := range map[string]bool{ + "abcdefghijklmnopqrstuvwxyzABCDEFG0987654321_-": true, + "$foo": false, + "bar$": false, + "foo\nbar": false, + } { + if aliasRegexp.MatchString(name) != shouldPass { + t.Errorf("name %q failed to pass its test", name) + } + } +}
pkg/plugin/plugin.go+10 −0 modified@@ -16,6 +16,7 @@ limitations under the License. package plugin // import "k8s.io/helm/pkg/plugin" import ( + "fmt" "io/ioutil" "os" "path/filepath" @@ -141,13 +142,22 @@ func LoadAll(basedir string) ([]*Plugin, error) { return plugins, nil } + loaded := map[string]bool{} for _, yaml := range matches { dir := filepath.Dir(yaml) p, err := LoadDir(dir) + pname := p.Metadata.Name if err != nil { return plugins, err } + + if _, ok := loaded[pname]; ok { + fmt.Fprintf(os.Stderr, "A plugin named %q already exists. Skipping.", pname) + continue + } + plugins = append(plugins, p) + loaded[pname] = true } return plugins, nil }
pkg/plugin/plugin_test.go+1 −0 modified@@ -137,6 +137,7 @@ func TestLoadAll(t *testing.T) { t.Fatalf("Could not load %q: %s", basedir, err) } + // This would fail if the duplicate plugin were loaded. if l := len(plugs); l != 3 { t.Fatalf("expected 3 plugins, found %d", l) }
pkg/plugin/testdata/plugdir/hello2/hello.sh+13 −0 added@@ -0,0 +1,13 @@ +#!/bin/bash + +echo "Hello from a Helm plugin" + +echo "PARAMS" +echo $* + +echo "ENVIRONMENT" +echo $TILLER_HOST +echo $HELM_HOME + +$HELM_BIN --host $TILLER_HOST ls --all +
pkg/plugin/testdata/plugdir/hello2/plugin.yaml+11 −0 added@@ -0,0 +1,11 @@ +name: "hello" +version: "0.1.0" +usage: "usage" +description: |- + description +command: "$HELM_PLUGIN_SELF/hello.sh" +useTunnel: true +ignoreFlags: true +install: "echo installing..." +hooks: + install: "echo installing..."
pkg/repo/index.go+24 −0 modified@@ -30,6 +30,7 @@ import ( "github.com/Masterminds/semver" "github.com/ghodss/yaml" + yaml2 "gopkg.in/yaml.v2" "k8s.io/helm/pkg/chartutil" "k8s.io/helm/pkg/proto/hapi/chart" @@ -83,6 +84,14 @@ type IndexFile struct { PublicKeys []string `json:"publicKeys,omitempty"` } +// IndexValidation is used to validate the integrity of an index file +type IndexValidation struct { + APIVersion string `yaml:"apiVersion"` + Generated time.Time `yaml:"generated"` + Entries map[string]interface{} `yaml:"entries"` + PublicKeys []string `yaml:"publicKeys,omitempty"` +} + // NewIndexFile initializes an index. func NewIndexFile() *IndexFile { return &IndexFile{ @@ -283,9 +292,14 @@ func IndexDirectory(dir, baseURL string) (*IndexFile, error) { // This will fail if API Version is not set (ErrNoAPIVersion) or if the unmarshal fails. func loadIndex(data []byte) (*IndexFile, error) { i := &IndexFile{} + if err := validateIndex(data); err != nil { + return i, err + } + if err := yaml.Unmarshal(data, i); err != nil { return i, err } + i.SortEntries() if i.APIVersion == "" { // When we leave Beta, we should remove legacy support and just @@ -296,6 +310,16 @@ func loadIndex(data []byte) (*IndexFile, error) { return i, nil } +// validateIndex validates that the index is well-formed. +func validateIndex(data []byte) error { + // This is done ONLY for validation. We need to use ghodss/yaml for the actual parsing. + validation := &IndexValidation{} + if err := yaml2.UnmarshalStrict(data, validation); err != nil { + return err + } + return nil +} + // unversionedEntry represents a deprecated pre-Alpha.5 format. // // This will be removed prior to v2.0.0
pkg/repo/index_test.go+16 −0 modified@@ -422,3 +422,19 @@ func TestIndexAdd(t *testing.T) { t.Errorf("Expected http://example.com/charts/deis-0.1.0.tgz, got %s", i.Entries["deis"][0].URLs[0]) } } + +const mockDuplicateIndex = ` +entries: + foo: {} + bar: {} + baz: {} + bar: {} +` + +func TestValidateIndex(t *testing.T) { + expect := `key "bar" already set in map` + err := validateIndex([]byte(mockDuplicateIndex)) + if strings.Contains(expect, err.Error()) { + t.Errorf("Unexpected error: %s", err) + } +}
Vulnerability mechanics
Generated by null/stub on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.
References
5- github.com/advisories/GHSA-jm56-5h66-w453ghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2020-15185ghsaADVISORY
- github.com/helm/helm/commit/055dd41cbe53ce131ab0357524a7f6729e6e40dcghsax_refsource_MISCWEB
- github.com/helm/helm/commit/6aab63765f99050b115f0aec3d6350c85e8da946ghsaWEB
- github.com/helm/helm/security/advisories/GHSA-jm56-5h66-w453ghsax_refsource_CONFIRMWEB
News mentions
0No linked articles in our index yet.