GHSA-grp3-h8m8-45p7

Summary

The Cassandra export module (glances/exports/glances_cassandra/__init__.py) interpolates keyspace, table, and replication_factor configuration values directly into CQL statements without validation. A user with write access to glances.conf can redirect all monitoring data to an attacker-controlled Cassandra keyspace.

Vulnerable Code

# Line 80
f"CREATE KEYSPACE {self.keyspace} WITH "
f"replication = {{ 'class': 'SimpleStrategy', 'replication_factor': '{self.replication_factor}' }}"

# Line 94
f"CREATE TABLE {self.table} (plugin text, time timeuuid, stat map<text,float>, PRIMARY KEY (plugin, time)) WITH CLUSTERING ORDER BY (time DESC)"

# Line 112
stmt = f"INSERT INTO {self.table} (plugin, time, stat) VALUES (?, ?, ?)"

Steps to Reproduce

1. Configure glances.conf with malicious table value:

   [cassandra]
   host = 127.0.0.1
   port = 9042
   keyspace = glances
   table = attacker_ks.captured_stats
   

2. Create attacker keyspace in Cassandra
3. Run glances --export cassandra
4. All monitoring data is written to attacker_ks.captured_stats instead of the legitimate table

Confirmed output:

INSERT stmt: INSERT INTO attacker_ks.captured_stats (plugin, time, stat) VALUES (?, ?, ?)
Legitimate table row count: 0
Attacker table row count: 1
[CONFIRMED] plugin=cpu, stat={'user': 50.0}

Impact

All exported monitoring data (CPU, memory, network, disk I/O) is silently redirected to an attacker-controlled Cassandra keyspace — both data exfiltration and data loss.

Proposed Fix

import re

def _validate_cql_identifier(name: str) -> str:
    if not re.match(r'^[a-zA-Z_][a-zA-Z0-9_.]*$', name):
        raise ValueError(f"Invalid CQL identifier: {name!r}")
    return name

# In __init__(): validate before use
self.keyspace = _validate_cql_identifier(self.keyspace)
self.table = _validate_cql_identifier(self.table)