login: T8415: show Warning() if default password is used when adding user

When performing an image installation and the user chooses vyos as the default
password, a warning is emitted.

The combination vyos/vyos is used in brute force lists and have been seen
multiple times in the wild. When adding the user via:
  set system login user vyos authentication plaintext-password vyos
a warning should be shown!

1 files changed, 5 insertions, 7 deletions

diff --git a/src/op_mode/image_installer.py b/src/op_mode/image_installer.py
index f0a347b73..41a9a89f9 100755
--- a/src/op_mode/image_installer.py
+++ b/src/op_mode/image_installer.py
@@ -49,19 +49,17 @@ from vyos.system import raid
 from vyos.system import SYSTEM_CFG_VER
 from vyos.system import grub_util
 from vyos.template import render
-from vyos.utils.auth import (
-    DEFAULT_PASSWORD,
-    EPasswdStrength,
-    evaluate_strength
-)
+from vyos.utils.auth import DEFAULT_PASSWORD
+from vyos.utils.auth import EPasswdStrength
+from vyos.utils.auth import evaluate_strength
+from vyos.utils.auth import get_local_users
+from vyos.utils.auth import get_user_home_dir
 from vyos.utils.dict import dict_search
 from vyos.utils.io import ask_input, ask_yes_no, select_entry
 from vyos.utils.file import chmod_2775
 from vyos.utils.file import read_file
 from vyos.utils.file import write_file
 from vyos.utils.process import cmd, run, rc_cmd
-from vyos.utils.auth import get_local_users
-from vyos.utils.auth import get_user_home_dir
 from vyos.version import get_version_data
 from vyos.config_mgmt import unsaved_commits