active-response

In the active response configuration section, an existing command is bound to one or more rules or rule types along with additional criteria for when to execute the command. There is no limit to the number of active responses that can be used, however, each active response must be configured in its own separate <active-response> section.

Options

disabled

Agent side

repeated_offenders
ca_store
ca_verification

disabled

Toggles the active-response capability on and off. Setting this option to yes on an agent will disable active-response for that agent only, while setting it in the manager's ossec.conf file will disable active-response on the manager and all agents.

Note

This option is available on server, local, and agent installations.

Default value	no
Allowed values	yes, no

command

Links the active-response to the command. You can find more information at the commands section.

Default value	n/a
Allowed values	Any defined active response command name

location

Indicates which system(s) the command should be executed on.

Default value	n/a
Allowed values	local	This runs the command on the agent that generated the event.
	server	This runs the command on the Wazuh manager.
	defined-agent	This runs the command on a specific agent identified by agent_id.
	all	This runs the command on all agents. Use with caution.

Example:

If the application that interfaces with your edge firewall runs on one of your agents, you might have a firewall-block-edge command that runs a script on that agent to blacklist an offending IP on the edge firewall.

agent_id

Specifies the ID of the agent on which to execute the active response command (used when defined-agent is set).

Default value	n/a
Allowed values	Any agent id number, as long as defined-agent has been specified as the location.

level

Defines a minimum severity level required for the command to be executed.

Default value	n/a
Allowed values	Any level from 1 to 16

rules_group

Defines the rule group that a rule must belong to one for the command to be executed.

Default value	n/a
Allowed values	Any rule group is allowed. Multiple groups should be separated with a pipe character (“\|”).

Note

All groups must end with a comma.

rules_id

Limits the command execution to only when one or more listed rules fire.

Default value	n/a
Allowed values	Any rule identification. Multiple IDs can be specified if separated by a comma.

Note

When setting level, rules_group and rules_id together, the active response will be triggered always that any rule matches with one of these options. In other words, they are accumulative options, not restrictive.

timeout

Specifies how long in seconds before the reverse command is executed. When repeated_offenders is used, timeout only applies to the first offense.

Default value	n/a
Allowed values	A positive number (seconds)

repeated_offenders

Sets timeouts in minutes for repeat offenders. This is a comma-separated list of increasing timeouts that can contain a maximum of 5 entries.

Default value	n/a
Allowed values	A positive number (minutes)

Warning

This option must be configured directly in the ossec.conf file of the agent, even when using a manager/agent setup with centralized configuration of other settings via agent.conf. Apart from that, it has to be defined in the upper <active-response> section found in the configuration file.

ca_store

Indicates the path to the root CA certificate. The agent needs the certificate with which the WPK was signed in order to be updated.

Default value	wpk_root.pem
Allowed values	Path to root CA certificate

ca_verification

This option enables or disables the WPK validation using the root CA certificate. If this parameter is set to no the agent will accept any WPK package coming from the manager.

Default value	yes
Allowed values	yes, no

Sample Configuration

<!-- On the manager side -->

<active-response>
  <disabled>no</disabled>
  <command>host-deny</command>
  <location>defined-agent</location>
  <agent_id>032</agent_id>
  <level>10</level>
  <rules_group>sshd,|pci_dss_11.4,</rules_group>
  <timeout>1</timeout>
</active-response>

<!-- On the agent side -->
<active-response>
  <disabled>no</disabled>
  <ca_store>/var/ossec/etc/wpk_root.pem</ca_store>
  <ca_verification>yes</ca_verification>
  <repeated_offenders>1,5,10</repeated_offenders>
</active-response>