Cacti sanitize_sql_column() Regex Allowlist Permits SQL Time-Delay Functions Leading to Blind SQL Injection

Cacti's sanitize_sql_column() (lib/functions.php) sanitizes user-supplied ORDER BY column names using the regex `preg_replace('/[^a-zA-Z0-9_().]/', '', $column)`. Because this allowlist retains letters, digits, underscore, parentheses, and dot (intended to support expressions like COUNT(id) and table.column), a payload such as `SLEEP(5)` passes through completely unmodified. The sanitized value is concatenated directly into raw SQL ORDER BY clauses (which cannot be parameterized) driven by a `sort_column` GET parameter in at least user_log.php, utilities.php, user_domains.php, and user_group_admin.php, allowing any authenticated Cacti user, regardless of privilege level, to perform time-based blind SQL injection against the Cacti database.