Cacti: community verdicts

Cacti is an open source platform which provides a robust and extensible operational monitoring and fault management framework for users. In affected versions a command injection vulnerability allows an unauthenticated user to execute arbitrary code on a server running Cacti, if a specific data source was selected for any monitored device. The vulnerability resides in the `remote_agent.php` file. This file can be accessed without authentication. This function retrieves the IP address of the client via `get_client_addr` and resolves this IP address to the corresponding hostname via `gethostbyaddr`. After this, it is verified that an entry within the `poller` table exists, where the hostname corresponds to the resolved hostname. If such an entry was found, the function returns `true` and the client is authorized. This authorization can be bypassed due to the implementation of the `get_client_addr` function. The function is defined in the file `lib/functions.php` and checks serval `$_SERVER` variables to determine the IP address of the client. The variables beginning with `HTTP_` can be arbitrarily set by an attacker. Since there is a default entry in the `poller` table with the hostname of the server running Cacti, an attacker can bypass the authentication e.g. by providing the header `Forwarded-For: <TARGETIP>`. This way the function `get_client_addr` returns the IP address of the server running Cacti. The following call to `gethostbyaddr` will resolve this IP address to the hostname of the server, which will pass the `poller` hostname check because of the default entry. After the authorization of the `remote_agent.php` file is bypassed, an attacker can trigger different actions. One of these actions is called `polldata`. The called function `poll_for_data` retrieves a few request parameters and loads the corresponding `poller_item` entries from the database. If the `action` of a `poller_item` equals `POLLER_ACTION_SCRIPT_PHP`, the function `proc_open` is used to execute a PHP script. The attacker-controlled parameter `$poller_id` is retrieved via the function `get_nfilter_request_var`, which allows arbitrary strings. This variable is later inserted into the string passed to `proc_open`, which leads to a command injection vulnerability. By e.g. providing the `poller_id=;id` the `id` command is executed. In order to reach the vulnerable call, the attacker must provide a `host_id` and `local_data_id`, where the `action` of the corresponding `poller_item` is set to `POLLER_ACTION_SCRIPT_PHP`. Both of these ids (`host_id` and `local_data_id`) can easily be bruteforced. The only requirement is that a `poller_item` with an `POLLER_ACTION_SCRIPT_PHP` action exists. This is very likely on a productive instance because this action is added by some predefined templates like `Device - Uptime` or `Device - Polling Time`. This command injection vulnerability allows an unauthenticated user to execute arbitrary commands if a `poller_item` with the `action` type `POLLER_ACTION_SCRIPT_PHP` (`2`) is configured. The authorization bypass should be prevented by not allowing an attacker to make `get_client_addr` (file `lib/functions.php`) return an arbitrary IP address. This could be done by not honoring the `HTTP_...` `$_SERVER` variables. If these should be kept for compatibility reasons it should at least be prevented to fake the IP address of the server running Cacti. This vulnerability has been addressed in both the 1.2.x and 1.3.x release branches with `1.2.23` being the first release containing the patch.

Cacti is an open source performance and fault management framework. Versions 1.2.30 and prior are vulnerable to Command Injection due to lack of sanitization in the escape_command() function. The escape_command() function at lib/rrd.php is a no-op: it returns $command unchanged. The command line built by rrdtool_function_graph() is passed through this function and then to shell_exec($full_commandline). The risk is in __rrd_execute() where text_format values from graph templates (which may contain host variable substitutions) reach shell_exec without adequate escaping. This issue has been addressed in version 1.2.31.

Cacti is an open source performance and fault management framework. In versions 1.2.30 and prior, the rfilter request parameter is retrieved via the raw accessor grv() (rather than gfrv() with FILTER_VALIDATE_IS_REGEX validation) and concatenated directly into RLIKE SQL clauses in lib/html_graph.php and lib/html_tree.php, which are reachable pre-authentication through graph_view.php on installations with guest graph viewing enabled. Because the unbalanced-quote payload bypasses the regex validation that would otherwise reject it, an unauthenticated attacker can inject arbitrary SQL to compromise the confidentiality, integrity, and availability of the database. This advisory is similar to GHSA-69gg-mjfm-jjpc. This issue has been fixed in version 1.2.31.

Cacti is an open source performance and fault management framework. Versions 1.2.30 and prior have unauthenticated LFI through graph_theme and rrdtool IPC serialization hardening. This issue has been resolved in version 1.2.31.

Cacti is an open source performance and fault management framework. In versions 1.2.30 and prior, the rfilter request variable was concatenated into a RLIKE SQL clause without sanitization. The endpoint does not require authentication (graph viewing supports guest access via the configured guest user), so the SQLi was reachable pre-auth on installs with guest viewing enabled. This issue was fixed in version 1.2.31.

Cacti is an open source performance and fault management framework. Versions 1.2.30 and prior have pre-authentication SQL Injection via unanchored FILTER_VALIDATE_REGEXP in graph_view.php. This issue has been fixed in version 1.2.31.

Cacti is an open source performance and fault management framework. Versions 1.2.30 and prior are vulnerable to Path Traversal via filename parameter in package_import.php. This issue has been fixed in version 1.2.31.

Cacti is an open source performance and fault management framework. Versions 1.2.30 and prior have a Stored SQL Injection vulnerability through graph_name_regexp in the Reports feature. This issue has been fixed in version 1.2.31.

Cacti is an open source performance and fault management framework. In versions 1.2.30 and below, the locale-dependent decimal formatting in rrdtool_function_update() can corrupt RRDtool metric values. The rrdtool_function_update() function checks metric values with is_numeric() and concatenates them into the RRDtool update command via PHP string interpolation. PHP's string cast of floats is locale-sensitive: if LC_NUMERIC uses comma as decimal separator (e.g., de_DE), a value of 1.5 becomes "1,5". RRDtool expects . as decimal separator, causing metric data to shift into wrong columns or be silently dropped. No setlocale() reset is present in the update path. This causes a data integrity issue, but is not remotely exploitable; it requires server locale misconfiguration. The issue has been fixed in version 1.2.31.