[security] fix: reject empty env allow wildcards

internal/cli/config_test.go

@@ -104,6 +104,41 @@ func clearConfigEnv(t *testing.T) {
 	}
 }
 
+func TestRepoConfigBareEnvWildcardDoesNotForwardEveryLocalVariable(t *testing.T) {
+	clearConfigEnv(t)
+	home := t.TempDir()
+	repo := t.TempDir()
+	t.Setenv("HOME", home)
+	t.Setenv("XDG_CONFIG_HOME", filepath.Join(home, ".config"))
+	t.Setenv("CRABBOX_CONFIG", "")
+	t.Setenv("CRABBOX_PROVIDER", "")
+	t.Setenv("CRABBOX_DEFAULT_CLASS", "")
+	t.Setenv("CRABBOX_PROOF_API_TOKEN", "critical-secret-value")
+	cwd, err := os.Getwd()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := os.Chdir(cwd); err != nil {
+			t.Fatal(err)
+		}
+	}()
+	if err := os.Chdir(repo); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(".crabbox.yaml", []byte("env:\n  allow:\n    - '*'\n"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+
+	cfg, err := loadConfig()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := allowedEnv(cfg.EnvAllow); got["CRABBOX_PROOF_API_TOKEN"] != "" {
+		t.Fatalf("bare wildcard forwarded proof secret: %q", got["CRABBOX_PROOF_API_TOKEN"])
+	}
+}
+
 func TestLoadConfigFromUserFile(t *testing.T) {
 	clearConfigEnv(t)
 	home := t.TempDir()

internal/cli/repo.go

@@ -131,7 +131,11 @@ func envAllowed(name string, allow []string) bool {
 			continue
 		}
 		if strings.HasSuffix(pattern, "*") {
-			if strings.HasPrefix(name, strings.TrimSuffix(pattern, "*")) {
+			prefix := strings.TrimSuffix(pattern, "*")
+			if prefix == "" {
+				continue
+			}
+			if strings.HasPrefix(name, prefix) {
 				return true
 			}
 			continue

internal/cli/ssh_test.go

@@ -209,6 +209,18 @@ func TestEnvAllowlist(t *testing.T) {
 	}
 }
 
+func TestEnvAllowlistRejectsEmptyWildcardPrefix(t *testing.T) {
+	if envAllowed("CRABBOX_PROOF_API_TOKEN", []string{"*"}) {
+		t.Fatal("bare wildcard must not forward every local environment variable")
+	}
+	if envAllowed("CRABBOX_PROOF_API_TOKEN", []string{"  *  "}) {
+		t.Fatal("trimmed bare wildcard must not forward every local environment variable")
+	}
+	if !envAllowed("PROJECT_FLAG", []string{"PROJECT_*"}) {
+		t.Fatal("non-empty prefix wildcard should still work")
+	}
+}
+
 func TestSSHArgsIncludeReliabilityOptions(t *testing.T) {
 	t.Setenv("HOME", "/tmp/crabbox-home")
 	got := strings.Join(sshArgs(SSHTarget{