CVE-2026-32634

Glances is an open-source system cross-platform monitoring tool. Prior to version 4.5.2, in Central Browser mode, Glances stores both the Zeroconf-advertised server name and the discovered IP address for dynamic servers, but later builds connection URIs from the untrusted advertised name instead of the discovered IP. When a dynamic server reports itself as protected, Glances also uses that same untrusted name as the lookup key for saved passwords and the global [passwords] default credential. An attacker on the same local network can advertise a fake Glances service over Zeroconf and cause the browser to automatically send a reusable Glances authentication secret to an attacker-controlled host. This affects the background polling path and the REST/WebUI click-through path in Central Browser mode. Version 4.5.2 fixes the issue.

Glances is an open-source system cross-platform monitoring tool. Prior to version 4.5.2, in Central Browser mode, Glances stores both the Zeroconf-advertised server name and the discovered IP address for dynamic servers, but later builds connection URIs from the untrusted advertised name instead of the discovered IP. When a dynamic server reports itself as protected, Glances also uses that same untrusted name as the lookup key for saved passwords and the global [passwords] default credential. An attacker on the same local network can advertise a fake Glances service over Zeroconf and cause the browser to automatically send a reusable Glances authentication secret to an attacker-controlled host. This affects the background polling path and the REST/WebUI click-through path in Central Browser mode. Version 4.5.2 fixes the issue.

Summary

In Central Browser mode, Glances stores both the Zeroconf-advertised server name and the discovered IP address for dynamic servers, but later builds connection URIs from the untrusted advertised name instead of the discovered IP. When a dynamic server reports itself as protected, Glances also uses that same untrusted name as the lookup key for saved passwords and the global [passwords] default credential.

An attacker on the same local network can advertise a fake Glances service over Zeroconf and cause the browser to automatically send a reusable Glances authentication secret to an attacker-controlled host. This affects the background polling path and the REST/WebUI click-through path in Central Browser mode.

Details

Dynamic server discovery keeps both a short name and a separate ip:

# glances/servers_list_dynamic.py:56-61
def add_server(self, name, ip, port, protocol='rpc'):
    new_server = {
        'key': name,
        'name': name.split(':')[0],  # Short name
        'ip': ip,  # IP address seen by the client
        'port': port,
        ...
        'type': 'DYNAMIC',
    }

The Zeroconf listener populates those fields directly from the service advertisement:

# glances/servers_list_dynamic.py:112-121
new_server_ip = socket.inet_ntoa(address)
new_server_port = info.port
...
self.servers.add_server(
    srv_name,
    new_server_ip,
    new_server_port,
    protocol=new_server_protocol,
)

However, the Central Browser connection logic ignores server['ip'] and instead uses the untrusted advertised server['name'] for both password lookup and the destination URI:

# 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

That URI is used automatically by the background polling thread:

# glances/servers_list.py:141-143
def __update_stats(self, server):
    server['uri'] = self.get_uri(server)

The password lookup itself falls back to the global default password when there is no exact match:

# glances/password_list.py:45-58
def get_password(self, host=None):
    ...
    try:
        return self._password_dict[host]
    except (KeyError, TypeError):
        try:
            return self._password_dict['default']
        except (KeyError, TypeError):
            return None

The sample configuration explicitly supports that default credential reuse:

# conf/glances.conf:656-663
[passwords]
# Define the passwords list related to the [serverlist] section
# ...
#default=defaultpassword

The secret sent over the network is not the cleartext password, but it is still a reusable Glances authentication credential. The client hashes the configured password and sends that hash over HTTP Basic authentication:

# 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

# glances/client.py:55-57
if args.password != "":
    self.uri = f'http://{args.username}:{args.password}@{args.client}:{args.port}'

There is an inconsistent trust boundary in the interactive browser code as well:

• glances/client_browser.py:44 opens the REST/WebUI target via webbrowser.open(self.servers_list.get_uri(server)), which again trusts server['name']
• glances/client_browser.py:55 fetches saved passwords with…

Glances is an open-source system cross-platform monitoring tool. Prior to version 4.5.2, in Central Browser mode, Glances stores both the Zeroconf-advertised server name and the discovered IP address for dynamic servers, but later builds connection URIs from the untrusted advertised name instead of the discovered IP. When a dynamic server reports itself as protected, Glances also uses that same untrusted name as the lookup key for saved passwords and the global [passwords] default credential. An attacker on the same local network can advertise a fake Glances service over Zeroconf and cause the browser to automatically send a reusable Glances authentication secret to an attacker-controlled host. This affects the background polling path and the REST/WebUI click-through path in Central Browser mode. Version 4.5.2 fixes the issue.

Glances is an open-source system cross-platform monitoring tool. Prior to version 4.5.2, in Central Browser mode, Glances stores both the Zeroconf-advertised server name and the discovered IP address for dynamic servers, but later builds connection URIs from the untrusted advertised name instead of the discovered IP. When a dynamic server reports itself as protected, Glances also uses that same untrusted name as the lookup key for saved passwords and the global [passwords] default credential. An attacker on the same local network can advertise a fake Glances service over Zeroconf and cause the browser to automatically send a reusable Glances authentication secret to an attacker-controlled host. This affects the background polling path and the REST/WebUI click-through path in Central Browser mode. Version 4.5.2 fixes the issue.

Glances is an open-source system cross-platform monitoring tool. Prior to version 4.5.2, in Central Browser mode, Glances stores both the Zeroconf-advertised server name and the discovered IP address for dynamic servers, but later builds connection URIs from the untrusted advertised name instead of the discovered IP. When a dynamic server reports itself as protected, Glances also uses that same untrusted name as the lookup key for saved passwords and the global [passwords] default credential. An attacker on the same local network can advertise a fake Glances service over Zeroconf and cause the browser to automatically send a reusable Glances authentication secret to an attacker-controlled host. This affects the background polling path and the REST/WebUI click-through path in Central Browser mode. Version 4.5.2 fixes the issue.