Glances's Browser API Exposes Reusable Downstream Credentials via `/api/4/serverslist`

## Summary In Central Browser mode, the `/api/4/serverslist` endpoint returns raw server objects from `GlancesServersList.get_servers_list()`. Those objects are mutated in-place during background polling and can contain a `uri` field with embedded HTTP Basic credentials for downstream Glances servers, using the reusable pbkdf2-derived Glances authentication secret. If the front Glances Browser/API instance is started without `--password`, which is supported and common for internal network deployments, `/api/4/serverslist` is completely unauthenticated. Any network user who can reach the Browser API can retrieve reusable credentials for protected downstream Glances servers once they have been polled by the browser instance. ## Details The Browser API route simply returns the raw servers list: ```python # glances/outputs/glances_restful_api.py:799-805 def _api_servers_list(self): self.__update_servers_list() return GlancesJSONResponse(self.servers_list.get_servers_list() if self.servers_list else []) ``` The main API router is only protected when the front instance itself was started with `--password`. Otherwise there are no authentication dependencies at all: ```python # glances/outputs/glances_restful_api.py:475-480 if self.args.password: router = APIRouter(prefix=self.url_prefix, dependencies=[Depends(self.authentication)]) else: router = APIRouter(prefix=self.url_prefix) ``` The Glances web server binds to `0.0.0.0` by default: ```python # glances/main.py:425-427 parser.add_argument( '--bind', default='0.0.0.0', dest='bind_address', ) ``` During Central Browser polling, server entries are modified in-place and gain a `uri` field: ```python # glances/servers_list.py:141-148 def __update_stats(self, server): server['uri'] = self.get_uri(server) ... if server['protocol'].lower() == 'rpc': self.__update_stats_rpc(server['uri'], server) elif server['protocol'].lower() == 'rest' and not import_requests_error_tag: self.__update_stats_rest(f"{server['uri']}/api/{__apiversion__}", server) ``` For protected servers, `get_uri()` loads the saved password from the `[passwords]` section (or the `default` password), hashes it, and embeds it directly in the URI: ```python # glances/servers_list.py:119-130 def get_uri(self, server): if server['password'] != "": if server['status'] == 'PROTECTED': clear_password = self.password.get_password(server['name']) if clear_password is not None: server['password'] = self.password.get_hash(clear_password) uri = 'http://{}:{}@{}:{}'.format( server['username'], server['password'], server['name'], server['port'], ) else: uri = 'http://{}:{}'.format(server['name'], server['port']) return uri ``` Password lookup falls back to a global default: ```python # glances/password_list.py:55-58 try: return self._password_dict[host] except (KeyError, TypeError): return self._password_dict['default'] ``` The sample configuration explicitly supports browser-wide default password reuse: ```ini # conf/glances.conf:656-663 [passwords] # localhost=abc # default=defaultpassword ``` The secret embedded in `uri` is not the cleartext password, but it is still a reusable Glances authentication credential. Client connections send that pbkdf2-derived hash over HTTP Basic authentication: ```python # glances/password.py:72-74,94 # For Glances client, get the password (confirm=False, clear=True): # 2) the password is hashed with SHA-pbkdf2_hmac (only SHA string transit password = password_hash ``` ```python # glances/client.py:56-57 if args.password != "": self.uri = f'http://{args.username}:{args.password}@{args.client}:{args.port}' ``` The Browser WebUI also consumes that raw `uri` directly and redirects the user to it: ```javascript // glances/outputs/static/js/Browser.vue:83-103 fetch("api/4/serverslist", { method: "GET" }) ... window.location.href = server.uri; ``` So once `server.uri` contains credentials, those credentials are not just used internally; they are exposed to API consumers and frontend JavaScript. ## PoC ### Step 1: Verified local live proof that server objects contain credential-bearing URIs The following command executes the real `glances/servers_list.py` update logic against a live local HTTP server that always returns `401`. This forces Glances to mark the downstream server as `PROTECTED` and then retry with the saved/default password. After the second refresh, the in-memory server list contains a `uri` field with embedded credentials. ```bash cd D:\bugcrowd\glances\repo @' import importlib.util import json import sys import threading import types from http.server import BaseHTTPRequestHandler, HTTPServer from pathlib import Path from defusedxml import xmlrpc as defused_xmlrpc pkg = types.ModuleType('glances') pkg.__apiversion__ = '4' sys.modules['glances'] = pkg client_mod = types.ModuleType('glances.client') class GlancesClientTransport(defused_xmlrpc.xmlrpc_client.Transport): def set_timeout(self, timeout): self.timeout = timeout client_mod.GlancesClientTransport = GlancesClientTransport sys.modules['glances.client'] = client_mod globals_mod = types.ModuleType('glances.globals') globals_mod.json_loads = json.loads sys.modules['glances.globals'] = globals_mod logger_mod = types.ModuleType('glances.logger') logger_mod.logger = types.SimpleNamespace( debug=lambda *a, **k: None, warning=lambda *a, **k: None, info=lambda *a, **k: None, error=lambda *a, **k: None, ) sys.modules['glances.logger'] = logger_mod password_list_mod = types.ModuleType('glances.password_list') class GlancesPasswordList: pass password_list_mod.GlancesPasswordList = GlancesPasswordList sys.modules['glances.password_list'] = password_list_mod dynamic_mod = types.ModuleType('glances.servers_list_dynamic') class GlancesAutoDiscoverServer:…