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Extension:AbuseFilter

Issue tracker: #AbuseFilter
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This extension comes with MediaWiki 1.38 and above. Thus you do not have to download it again. However, you still need to follow the other instructions provided.
MediaWiki extensions manual
AbuseFilter
Release status: stable
Implementation User activity , Special page , API
Description Allows specific behavior-based restrictions to be placed on wiki activity
Author(s)
Compatibility policy Snapshots releases along with MediaWiki. Master is not backward compatible.
MediaWiki >= 1.43.0
Database changes Yes
Composer mediawiki/abuse-filter
Tables abuse_filter
abuse_filter_action
abuse_filter_history
abuse_filter_log
License GNU General Public License 2.0 or later
Download
Download extension
Git [?]:
Parameters
  • $wgAbuseFilterConditionLimit
  • $wgAbuseFilterRangeBlockSize
  • $wgAbuseFilterAnonBlockDuration
  • $wgAbuseFilterLogIPMaxAge
  • $wgAbuseFilterCentralDB
  • $wgAbuseFilterDefaultWarningMessage
  • $wgAbuseFilterEmergencyDisableAge
  • $wgAbuseFilterEnableBlockedExternalDomain
  • $wgAbuseFilterActionRestrictions
  • $wgAbuseFilterActions
  • $wgAbuseFilterProtectedVariables
  • $wgAbuseFilterLogIP
  • $wgAbuseFilterPrivateDetailsForceReason
  • $wgAbuseFilterEmergencyDisableCount
  • $wgAbuseFilterLogPrivateDetailsAccess
  • $wgAbuseFilterSlowFilterRuntimeLimit
  • $wgAbuseFilterEmergencyDisableThreshold
  • $wgAbuseFilterLocallyDisabledGlobalActions
  • $wgAbuseFilterBlockDuration
  • $wgAbuseFilterDefaultDisallowMessage
  • $wgAbuseFilterValidGroups
  • $wgAbuseFilterNotificationsPrivate
  • $wgAbuseFilterBlockAutopromoteDuration
  • $wgAbuseFilterIsCentral
  • $wgAbuseFilterNotifications
Added rights
  • abusefilter-modify
  • abusefilter-log-detail
  • abusefilter-view
  • abusefilter-log
  • abusefilter-privatedetails
  • abusefilter-privatedetails-log
  • abusefilter-modify-restricted
  • abusefilter-revert
  • abusefilter-view-private
  • abusefilter-log-private
  • abusefilter-hidden-log
  • abusefilter-hide-log
  • abusefilter-modify-global
  • abusefilter-modify-blocked-external-domains
  • abusefilter-bypass-blocked-external-domains
  • abusefilter-access-protected-vars
Hooks used
Hooks provided
Quarterly downloads 138 (Ranked 41st)
Public wikis using 2,939 (Ranked 186th)
Translate the AbuseFilter extension if it is available at translatewiki.net
Issues Open tasks · Report a bug

AbuseFilter

2020 Coolest Tool
Award Winner

in the category
Quality


The AbuseFilter extension allows privileged users to set specific actions to be taken when actions by users, such as edits, match certain criteria.

For example, a filter could be created to prevent unregistered users from adding external links, or to block a user who removes more than 2000 characters.


Installation

  • Download and move the extracted AbuseFilter folder to your extensions/ directory.
    Developers and code contributors should install the extension from Git instead, using:cd extensions/
    git clone https://gerrit.wikimedia.org/r/mediawiki/extensions/AbuseFilter
  • Only when installing from Git, run Composer to install PHP dependencies, by issuing composer install --no-dev in the extension directory. (See task T173141 for potential complications.)
  • Add the following code at the bottom of your LocalSettings.php file: 
    wfLoadExtension( 'AbuseFilter' );
  • Run the update script which will automatically create the necessary database tables that this extension needs.
  • Configure as required.
  • Yes Done – Navigate to Special:Version on your wiki to verify that the extension is successfully installed.
When installing from Git, please note that this extension requires Composer .

So, after installation from Git change to the directory containing the extension e.g. "../extensions/AbuseFilter/" and run composer install --no-dev, or when updating: composer update --no-dev.

Alternatively as well as preferably add the line "extensions/AbuseFilter/composer.json" to the "composer.local.json" file in the root directory of your wiki like e.g. 

{
	"extra": {
		"merge-plugin": {
			"include": [
				"extensions/AbuseFilter/composer.json"
			]
		}
	}
}

Configuration

User rights

Once you installed the extension, you'll have to set up the user rights in "LocalSettings.php".

User rights for AbuseFilter
Right Description Notes User groups that have this right by default
abusefilter-modify Create or modify abuse filters Requires the abusefilter-view right sysop
abusefilter-view View abuse filters *
abusefilter-log View the abuse log *
abusefilter-log-detail View detailed abuse log entries Requires the abusefilter-log right sysop
abusefilter-privatedetails View private data in the abuse log Prior to 1.34 this right was named abusefilter-private - Requires the abusefilter-log-detail right —
abusefilter-modify-restricted Modify abuse filters with restricted actions Requires the abusefilter-modify right sysop
abusefilter-modify-global Create or modify global abuse filters Requires the abusefilter-modify right —
abusefilter-revert Revert all changes by a given abuse filter sysop
abusefilter-view-private View abuse filters marked as private Requires the abusefilter-view right (not needed if the group already has the abusefilter-modify right) sysop
abusefilter-log-private View log entries of abuse filters marked as private Requires the abusefilter-log right (not needed if the group already has the abusefilter-modify or abusefilter-view-private rights) sysop
abusefilter-hide-log Hide entries in the abuse log Requires the abusefilter-log right suppress
abusefilter-hidden-log View hidden abuse log entries Requires the abusefilter-log right suppress
abusefilter-privatedetails-log View the AbuseFilter private details access log Prior to 1.34 this right was named abusefilter-private-log —
abusefilter-modify-blocked-external-domains Create or modify what external domains are blocked from being linked sysop
abusefilter-bypass-blocked-external-domains Bypass blocked external domains Requires the edit right bot

For example, the following sample configuration would allow sysops to do everything they want with AbuseFilter, and everyone to view the log and see public filter settings: 

$wgGroupPermissions['sysop']['abusefilter-modify'] = true;
$wgGroupPermissions['*']['abusefilter-log-detail'] = true;
$wgGroupPermissions['*']['abusefilter-view'] = true;
$wgGroupPermissions['*']['abusefilter-log'] = true;
$wgGroupPermissions['sysop']['abusefilter-privatedetails'] = true;
$wgGroupPermissions['sysop']['abusefilter-modify-restricted'] = true;
$wgGroupPermissions['sysop']['abusefilter-revert'] = true;
Filters marked as private can only be viewed by users with either the abusefilter-modify or abusefilter-view-private permission.

Parameters

Variable name Default value Description
$wgAbuseFilterActions 
[
    'throttle' => true,
    'warn' => true,
    'disallow' => true,
    'blockautopromote' => true,
    'block' => true,
    'rangeblock' => false,
    'degroup' => false,
    'tag' => true
]
The possible actions that can be taken by abuse filters. When adding a new action, check if it is restricted in $wgAbuseFilterActionRestrictions and, if it is, don't forget to add the abusefilter-modify-restricted right to the appropriate user groups.
$wgAbuseFilterConditionLimit 
1000
The maximum number of 'conditions' that can be used each time the filters are run against a change. (More complex filters require more 'conditions').
$wgAbuseFilterValidGroups 
[
    'default'
]
The list of "groups" filters can be divided into. By default there is only one group. Other extensions may add other groups.
$wgAbuseFilterEmergencyDisableThreshold 
[
    'default' => 0.05
]
Disable a filter if it matched more than 2 edits, constituting more than 5 % of the actions which were checked against the filter's group in the "observed" period (at most one day), and the filter has been changed in the last 86400 seconds (one day). See emergency throttling.
$wgAbuseFilterEmergencyDisableCount 
[
    'default' => 2
]
$wgAbuseFilterEmergencyDisableAge 
[
    'default' => 86400
]
$wgAbuseFilterActionRestrictions 
[
	"throttle" => false,
	"warn" => false,
	"disallow" => false,
	"blockautopromote" => true,
	"block" => true,
	"rangeblock" => true,
	"degroup" => true,
	"tag" => false
]
Users must have the "abusefilter-modify-restricted" user right as well as "abusefilter-modify" in order to create or modify filters which carry out these actions.
$wgAbuseFilterNotifications 
false
Allows to configure the extension to send hit notifications to Special:RecentChanges or UDP. Available options: rc, udp, rcandudp
For sending changes to abuse filters to Special:RecentChanges, use unset($wgLogRestrictions['abusefilter']);.
$wgAbuseFilterNotificationsPrivate 
false
Enable notifications for private filters.
$wgAbuseFilterCentralDB 
null
MW 1.41+ Name of a database where global abuse filters will be stored in. Requires CentralAuth installed otherwise global filters will break on a wikifarm.
$wgAbuseFilterIsCentral 
false
MW 1.41+ Set this variable to true for the wiki where global AbuseFilters are stored in. Requires CentralAuth installed otherwise global filters will break on a wikifarm.
$wgAbuseFilterLocallyDisabledGlobalActions 
[
	"throttle" => false,
	"warn" => false,
	"disallow" => false,
	"blockautopromote" => false,
	"block" => false,
	"rangeblock" => false,
	"degroup" => false,
	"tag" => false
]
Disallow Centralised filters from taking actions set as true in this variable.
$wgAbuseFilterBlockDuration 
'indefinite'
Duration of blocks made by AbuseFilter.
as of 1.31.0-wmf.25 block durations may be specified for every single filter and will override this variable. This variable is only used when enabling the block in order to preselect a default duration.
$wgAbuseFilterAnonBlockDuration 
null
Duration of blocks made by AbuseFilter on users who are not logged in. The value of $wgAbuseFilterBlockDuration will be used if this is not set.
as of 1.31.0-wmf.25 block durations may be specified for every single filter and will override this variable. This variable is only used when enabling the block in order to preselect a default duration.
$wgAbuseFilterBlockAutopromoteDuration 
5
Duration, in days, for which users' autopromotion is blocked by filters.
$wgAbuseFilterDefaultWarningMessage 
[
    'default' => 'abusefilter-warning'
]
Default warning messages, per filter group
$wgAbuseFilterDefaultDisallowMessage 
[
    'default' => 'abusefilter-disallowed'
]
Default disallow messages, per filter group
$wgAbuseFilterLogIP 
true
Whether to include IP in the abuse_filter_log
$wgAbuseFilterLogIPMaxAge 
3 * 30 * 24 * 3600
Age used as cutoff when purging old IP log data. Defaults to 3 months. Used by maintenance script purgeOldLogIPData.php.
$wgAbuseFilterProfileActionsCap 
10000
Number of action that determines when to reset profiling stats.
$wgAbuseFilterLogPrivateDetailsAccess 
false
Whether accessing private information from a filter log entry is logged.
$wgAbuseFilterPrivateDetailsForceReason 
false
Whether users are forced to provide a reason for accessing private information from a filter log entry.
$wgAbuseFilterSlowFilterRuntimeLimit 
500
Runtime in milliseconds before a filter is considered slow.
$wgAbuseFilterRangeBlockSize 
[
    'IPv4' => '16',
    'IPv6' => '19',
]
Size of the range blocked by 'rangeblock' action.

Emergency throttling

AbuseFilter comes with a feature that automatically throttles (disables) filters that have been edited recently and match a certain threshold of the latest actions.

This is done to prevent harmful edits on the filters to block every user that performs an action on the wiki or similar.

The condition to disable the filter depend on those variables:

  • $wgAbuseFilterEmergencyDisableThreshold - Percent of matches over the total amount of actions in the observed period.
  • $wgAbuseFilterEmergencyDisableCount - Count of matches of the filter in the observed period.
  • $wgAbuseFilterEmergencyDisableAge - Age of the filter to take it into account. If the last edit of the filter is older than this number of seconds, the filter won't be throttled, unless it's already throttled.

Throttled filters can be identified in the list of filters (Special:AbuseFilter) with the state Enabled, High rate of matches. Throttling happens silently, and there's no way to see when a filter got throttled, except when Extension:Echo is installed, then a notification is sent to the user who was last to modify the filter.

When a filter gets throttled, it doesn't perform any dangerous action (actions usually restricted to special rights like blocking the user, or removing it from groups, controlled by $wgAbuseFilterActionRestrictions), and only "safe" actions are allowed (the ones that can warn or prevent the ongoing action). Throttled filters don't get enabled automatically. To disable the throttling, you need to edit the filter. Note that you need to actually change something from the filter: changing something from the filter's notes is sufficient.

Note that editing the filter updates its age, and can cause it to be disabled if it reaches again the conditions to be throttled in a short period since the last edit, leading to a unusable filter if your wiki has more abuse edits than legitimate ones.

Creating and managing filters

Once the extension has been installed, filters can be created/tested/changed/deleted and the logs can be accessed from the Abuse filter management page Special:AbuseFilter.

API

AbuseFilter adds two API list modules, one for details of abuse filters ("abusefilters") and one for the abuse log, since it is separate from other MediaWiki logs ("abuselog"). It is not possible to create or modify abuse filters using the API.

list = abusefilters

List information about filters

Parameters
  • abfstartid - The filter id to start enumerating from
  • abfendid - The filter id to stop enumerating at
  • abfdir - The direction in which to enumerate (older, newer)
  • abfshow - Show only filters which meet these criteria (enabled|!enabled|deleted|!deleted|private|!private)
  • abflimit - The maximum number of filters to list
  • abfprop - Which properties to get (id|description|pattern|actions|hits|comments|lasteditor|lastedittime|status|private)

When filters are private, some of the properties specified with abfprop will be missing unless you have the appropriate user rights.

Examples
List non-private abuse filters
api.php?action=query&list=abusefilters&abfshow=!private&abfprop=id|hits [try in ApiSandbox]
Result
{
    "batchcomplete": "",
    "continue": {
        "abfstartid": 18,
        "continue": "-||"
    },
    "query": {
        "abusefilters": [
            {
                "id": 1,
                "hits": 41430
            },
            {
                "id": 3,
                "hits": 957485
            },
            {
                "id": 5,
                "hits": 5931
            },
            {
                "id": 6,
                "hits": 19
            },
            {
                "id": 8,
                "hits": 7
            },
            {
                "id": 9,
                "hits": 41354
            },
            {
                "id": 11,
                "hits": 132971
            },
            {
                "id": 12,
                "hits": 139693
            },
            {
                "id": 14,
                "hits": 63
            },
            {
                "id": 15,
                "hits": 15
            }
        ]
    }
}

list = abuselog

List instances where actions triggered an abuse filter.

Parameters
  • aflstart - The timestamp to start enumerating from
  • aflend - The timestamp to stop enumerating at
  • afldir - The direction in which to enumerate (older, newer)
  • afluser - Show only entries where the action was attempted by a given user or IP address.
  • afltitle - Show only entries where the action involved a given page.
  • aflfilter - Show only entries that triggered a given filter ID
  • afllimit - The maximum number of entries to list
  • aflprop - Which properties to get: (ids|filter|user|ip|title|action|details|result|timestamp|hidden|revid|wiki)
Example
List instances where the abuse filter was triggered in response to actions from the user "SineBot"
api.php?action=query&list=abuselog&afluser=SineBot&aflprop=ids [try in ApiSandbox]
Result
{
    "batchcomplete": "",
    "continue": {
        "aflstart": "2018-03-06T02:34:18Z",
        "continue": "-||"
    },
    "query": {
        "abuselog": [
            {
                "id": 27219261,
                "filter_id": "1073"
            },
            {
                "id": 26938051,
                "filter_id": ""
            },
            {
                "id": 23388942,
                "filter_id": "1"
            },
            {
                "id": 22044912,
                "filter_id": ""
            },
            {
                "id": 22032235,
                "filter_id": ""
            },
            {
                "id": 22032196,
                "filter_id": ""
            },
            {
                "id": 21983882,
                "filter_id": ""
            },
            {
                "id": 20594818,
                "filter_id": "904"
            },
            {
                "id": 20593489,
                "filter_id": "904"
            },
            {
                "id": 20590442,
                "filter_id": "904"
            }
        ]
    }
}

Possible errors

  • Some users might experience that creating new filters or modifying old filters fail and the user just gets redirected to the original page. If the Wiki is using SSL certificates, this error could possibly be because of the $wgServer value, which might be using "http://" instead of "https://". An indication of this error will be, the browser giving https warning for Special:AbuseFilter pages. (Topic:T23dyyih0ofjada5)

Integration with other extensions

You can integrate AbuseFilter with other extension in various ways.

Adding variables for filtering

It is possible to add new variables, to be used in abuse filters. A list of examples is available . To do that, you should:

  • Add a handler for the AbuseFilter-builder hook. To add a variable, you should use $builder['vars']['variable_name'] = 'i18n-key';, where variable_name is the name of the variable, and i18n-key is the fragment of an i18n key. The full key will be abusefilter-edit-builder-vars-{$your_key}.
  • Add the i18n messages you chose at the previous point.
  • Choose a hook handler where the variable will be computed. Depending on your use case, you could:
    • Implement the AbuseFilter-generateTitleVars hook; this is specifically thought for page-related variables;
    • Implement the AbuseFilter-generateUserVars hook; this is specifically thought for user-related variables;
    • Implement the AbuseFilter-generateGenericVars hook; this is for variables not bound to a specific page or user;
    • Implement the AbuseFilterAlterVariables hook; this is a bit more flexible than the other hooks, but it has a downside: your variable will not be available when examining past RecentChanges entries. If you want to implement that feature (and it's recommended to do so), you should use one of the hooks listed above, and use its third parameter ($RCRow).
  • Inside the hook handler, there are two ways to add a variable:
    • The "direct" way is calling $vars->setVar( 'var_name', var_value );. This is ideal only when the value is easy and quick to compute: the value is computed even if no active filter will use it.
    • The "lazy" way is calling $vars->setLazyLoadVar( 'var_name', 'method_name', $params );. Here, 'method_name' is a (unique) identifier that will be used to compute the variable (it's recommended to prefix it with the name of your extension). To register the method, you should add a handler for the AbuseFilter-computeVariable hook; therein, you should check if the $method passed matches your 'method_name', and if so, compute the variable. Lastly, $params is an array of parameters that you'll need to compute the variable; these are passed to the computeVariable hook handler. For an example of this, you can check out CentralAuth's global_user_groups.

Adding custom actions

You can add custom action handlers, so that each filter may perform further actions. To do that, you choose a name for the action ('my-action' from now on), and then:

  • Create a class named e.g. MyAction, that should extend \MediaWiki\Extension\AbuseFilter\Consequence, which can also implement HookAborterConsequence or ConsequencesDisablerConsequence
  • Add a subscriber to the AbuseFilterCustomActions hook; the subscriber should provide a callback as documented in the hook documentation, that returns an instance of the class created above, for instance:
class MyAction extends \MediaWiki\Extension\AbuseFilter\Consequence {
    public function run() {
        throw new \Exception( 'Write me' );
    }
}

public function onAbuseFilterCustomActions( &$actions ) {
    $actions[] = function ( \MediaWiki\Extension\AbuseFilter\Consequence\Parameters $params, array $rawParams ) : MyConsequence {
        return new MyAction( $params, $rawParams );
    };
}

Then you should add the following i18n messages; you can replace 'my_action' with e.g. 'block' to see what the messages are for:

  • 'abusefilter-edit-action-${my_action}'
  • 'abusefilter-action-${my_action}'

Adding rule groups

You can also add extra rule groups, which can be used to group existing abuse filters. Note that, at the moment, each filter can only be in a single group (T116642). Currently, the only known consumer of this feature is Extension:StructuredDiscussions . To do that, you should:

  • Append the name of the group to $wgAbuseFilterValidGroups.
  • Add some code to run the filters with your group. Note that AbuseFilter won't do that on its own. To do that, you should construct an AbuseFilterRunner object, passing in the name of your group.

See also

Retrieved from "https://www.mediawiki.org/w/index.php?title=Extension:AbuseFilter&oldid=6804707"