alpine 3.9
shell weakness #4


Weakness Breakdown


A shell weakness occurs when a program enables an attacker to execute unexpected commands on the operating system.

Warning code(s):

This causes a new program to execute and is difficult to use safely.

File Name:



The highlighted line of code below is the trigger point of this particular Alpine 3.9 shell weakness.


static gboolean
did_not_receive_signal (gpointer user_data)
  g_assert_not_reached ();

static void
test_signal_receipt (void)
  GError *error = NULL;
  GVariant *reply;
  gint status;
  guint id;

  reply = dconf_engine_dbus_call_sync_func (G_BUS_TYPE_SESSION,
                                            "org.freedesktop.DBus", "/", "org.freedesktop.DBus", "AddMatch",
                                            g_variant_new ("(s)", "type='signal',interface='ca.desrt.dconf.Writer'"),
                                            G_VARIANT_TYPE_UNIT, &error);
  g_assert_no_error (error);
  g_assert (reply != NULL);
  g_variant_unref (reply);

  status = system ("gdbus emit --session "
                   "--object-path /ca/desrt/dconf/Writer/testcase "
                   "--signal ca.desrt.dconf.Writer.TestSignal "
                   "\"'1'\" \"['2', '3']\"");
  g_assert_cmpint (status, ==, 0);

  id = g_timeout_add (30000, did_not_receive_signal, NULL);
  while (!signal_was_received)
    g_main_context_iteration (NULL, FALSE);
  g_source_remove (id);

main (int argc, char **argv)
  g_test_init (&argc, &argv, NULL);

  main_thread = g_thread_self ();

  dconf_engine_dbus_init_for_testing ();

  /* test_creation_error absolutely must come first */
  if (!g_str_equal (DBUS_BACKEND, "/libdbus-1"))
    g_test_add_func (DBUS_BACKEND "/creation/error", test_creation_error);

  g_test_add_func (DBUS_BACKEND "/sync-call/success", test_sync_call_success); 

The registered trademark Linux® is used pursuant to a sublicense from the Linux Foundation, the exclusive licensee of Linus Torvalds, owner of the mark on a world­wide basis.