apply fix (#42969)

pkg/plugins/plugins.go

@@ -491,15 +491,15 @@ func GetPluginMarkdown(pluginId string, name string) ([]byte, error) {
 	}
 
 	// nolint:gosec
-	// We can ignore the gosec G304 warning on this one because `plug.PluginDir` is based
-	// on plugin the folder structure on disk and not user input.
-	path := filepath.Join(plug.PluginDir, fmt.Sprintf("%s.md", strings.ToUpper(name)))
+	// We can ignore the gosec G304 warning since we have cleaned the requested file path and subsequently
+	// use this with a prefix of the plugin's directory, which is set during plugin loading
+	path := filepath.Join(plug.PluginDir, mdFilepath(strings.ToUpper(name)))
 	exists, err := fs.Exists(path)
 	if err != nil {
 		return nil, err
 	}
 	if !exists {
-		path = filepath.Join(plug.PluginDir, fmt.Sprintf("%s.md", strings.ToLower(name)))
+		path = filepath.Join(plug.PluginDir, mdFilepath(strings.ToLower(name)))
 	}
 
 	exists, err = fs.Exists(path)
@@ -511,8 +511,8 @@ func GetPluginMarkdown(pluginId string, name string) ([]byte, error) {
 	}
 
 	// nolint:gosec
-	// We can ignore the gosec G304 warning on this one because `plug.PluginDir` is based
-	// on plugin the folder structure on disk and not user input.
+	// We can ignore the gosec G304 warning since we have cleaned the requested file path and subsequently
+	// use this with a prefix of the plugin's directory, which is set during plugin loading
 	data, err := ioutil.ReadFile(path)
 	if err != nil {
 		return nil, err
@@ -520,6 +520,10 @@ func GetPluginMarkdown(pluginId string, name string) ([]byte, error) {
 	return data, nil
 }
 
+func mdFilepath(mdFilename string) string {
+	return filepath.Clean(filepath.Join("/", fmt.Sprintf("%s.md", mdFilename)))
+}
+
 // gets plugin filenames that require verification for plugin signing
 func collectPluginFilesWithin(rootDir string) ([]string, error) {
 	var files []string