assert_str_beginswith(GString *expected, gchar *actual) {
    gchar *actual_beginning = g_strndup(actual, expected->len);
    g_assert_cmpstr(expected->str, ==, actual_beginning);
    g_free(actual_beginning);

    /* return the part of the actual string that hasn't been compared yet */
    return &actual[expected->len];
}

This category addresses vulnerabilities caused by flawed access control mechanisms, where incorrect permission settings allow unauthorized users to access restricted resources.