defender-security / src / component / security-tweaks / class-prevent-enum-users.php

class-prevent-enum-users.php in Defender Security – Malware Scanner, Login Security & Firewall 6.2.3, at src/component/security-tweaks/class-prevent-enum-users.php

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1	<?php
2	/**
3	* Prevents user enumeration on a WordPress site to enhance security by blocking various endpoints and methods that can
4	* be used to discover user information.
5	*
6	* @package WP_Defender\Component\Security_Tweaks
7	*/
8
9	namespace WP_Defender\Component\Security_Tweaks;
10
11	use WP_Error;
12	use WP_REST_Response;
13	use WP_Sitemaps_Provider;
14	use WP_Defender\Traits\Security_Tweaks_Option;
15
16	/**
17	* Prevent user enumeration.
18	*/
19	class Prevent_Enum_Users extends Abstract_Security_Tweaks implements Security_Key_Const_Interface {
20
21	use Security_Tweaks_Option;
22
23	/**
24	* The slug identifier for this tweak.
25	*
26	* @var string
27	*/
28	public string $slug = 'prevent-enum-users';
29
30	/**
31	* Status to check if the issue has been resolved.
32	*
33	* @var bool
34	*/
35	public $resolved = false;
36
37	/**
38	* Enabled user enumerations list.
39	*
40	* @var array
41	*/
42	private $enabled_user_enums = array();
43
44	/**
45	* Check whether the issue has been resolved or not.
46	*
47	* @return bool
48	*/
49	public function check(): bool {
50	return $this->resolved;
51	}
52
53	/**
54	* Here is the code for processing.
55	*
56	* @return bool
57	*/
58	public function process(): bool {
59	return true;
60	}
61
62	/**
63	* This is for un-do stuff that has been done in @process.
64	*
65	* @return bool
66	*/
67	public function revert(): bool {
68	return true;
69	}
70
71	/**
72	* Shield up.
73	*
74	* @return void
75	*/
76	public function shield_up() {
77	$this->resolved = true;
78
79	if ( is_admin() \|\| defender_is_wp_cli() ) {
80	return;
81	}
82
83	add_filter( 'oembed_response_data', array( $this, 'oembed_author_filter' ), 99 );
84	add_filter( 'wp_sitemaps_users_pre_url_list', array( $this, 'block_user_url_sitemap' ), 99, 0 );
85	add_filter( 'wp_sitemaps_add_provider', array( $this, 'block_user_provider_sitemap' ), 99, 2 );
86	add_filter( 'rest_authentication_errors', array( $this, 'block_rest_api_user_endpoint' ) );
87	add_filter( 'rest_endpoints', array( $this, 'block_rest_api_user_endpoints' ), 99 );
88	add_action( 'rest_api_init', array( $this, 'register_dynamic_post_type_filters' ) );
89
90	$query = defender_get_data_from_request( 'QUERY_STRING', 's' );
91	if ( ! is_string( $query ) \|\| '' === $query ) {
92	return;
93	}
94
95	$this->maybe_block( $query );
96
97	add_filter( 'redirect_canonical', array( $this, 'maybe_block' ) );
98	}
99
100	/**
101	* Maybe block the request if it's trying to access the author page with query param.
102	*
103	* @param string $request Request of current page.
104	*
105	* @return string
106	*/
107	public function maybe_block( string $request ) {
108	if ( ! current_user_can( 'edit_others_posts' ) ) {
109	$params = array();
110	wp_parse_str( strtolower( $request ), $params );
111
112	if (
113	isset( $params['author'] )
114	&& is_scalar( $params['author'] )
115	&& '' !== preg_replace( '/[^0-9,-]/', '', $params['author'] )
116	) {
117	wp_die(
118	esc_html__( 'Sorry, you are not allowed to access this page', 'defender-security' ),
119	esc_html__( 'Forbidden', 'defender-security' ),
120	403
121	);
122	}
123	}
124
125	return $request;
126	}
127
128	/**
129	* Retrieve the tweak's label.
130	*
131	* @return string
132	*/
133	public function get_label(): string {
134	return esc_html__( 'Prevent user enumeration', 'defender-security' );
135	}
136
137	/**
138	* Get the error reason.
139	*
140	* @return string
141	*/
142	public function get_error_reason(): string {
143	return wp_kses(
144	__( '<strong>User enumeration is currently allowed</strong> and may expose your site.', 'defender-security' ),
145	array(
146	'strong' => array(),
147	)
148	);
149	}
150
151	/**
152	* Return a summary data of this tweak.
153	*
154	* @return array
155	*/
156	public function to_array(): array {
157	$enabled = $this->get_enabled_user_enums();
158	$stop_rest = in_array( 'enum-rest', $enabled, true );
159	$hide_user = in_array( 'enum-oembed', $enabled, true );
160	$disable_maps = in_array( 'enum-sitemap', $enabled, true );
161	$all_enabled = $stop_rest && $hide_user && $disable_maps;
162
163	$success_reason = $all_enabled
164	? wp_strip_all_tags( __( 'All recommendation settings are turned on.', 'defender-security' ) )
165	: wp_strip_all_tags( __( 'Custom recommendation settings are turned on.', 'defender-security' ) );
166
167	return array(
168	'slug' => $this->slug,
169	'title' => $this->get_label(),
170	'errorReason' => $this->get_error_reason(),
171	'successReason' => $success_reason,
172	'misc' => array(
173	'show_revert_button' => true,
174	'show_action_button' => true,
175	'stop_rest_api' => $stop_rest,
176	'hide_user_id' => $hide_user,
177	'disable_author_sitemap' => $disable_maps,
178	),
179	'bulk_description' => wp_strip_all_tags( __( 'Author redirects can make usernames easier for bots to find. Prevent user enumeration to protect your login area and reduce brute force risk.', 'defender-security' ) ),
180	'bulk_title' => wp_strip_all_tags( __( 'Prevent user enumeration', 'defender-security' ) ),
181	);
182	}
183
184	/**
185	* Getter method of enabled_user_enums.
186	*
187	* @return array Return array of enabled enumeration options.
188	*/
189	public function get_enabled_user_enums(): array {
190	$enabled_user_enums = $this->get_option( 'enabled_user_enums' );
191
192	$this->enabled_user_enums = is_null( $enabled_user_enums )
193	? array()
194	: (array) $enabled_user_enums;
195
196	return $this->enabled_user_enums;
197	}
198
199	/**
200	* Setter method of enabled_user_enums.
201	*
202	* @param array $value Array of enabled user enumeration options.
203	*
204	* @return bool Return true if value updated, otherwise false.
205	*/
206	public function set_enabled_user_enums( $value ): bool {
207	$this->enabled_user_enums = ! is_array( $value ) ? (array) $value : $value;
208
209	return $this->update_option(
210	'enabled_user_enums',
211	$this->enabled_user_enums
212	);
213	}
214
215	/**
216	* Filters the author detail from oEmbed response data.
217	*
218	* @param array $data The response data.
219	*
220	* @return array $data The response data.
221	*/
222	public function oembed_author_filter( $data ) {
223	if (
224	is_array( $data ) &&
225	in_array(
226	'enum-oembed',
227	$this->get_enabled_user_enums(),
228	true
229	)
230	) {
231	unset( $data['author_name'], $data['author_url'] );
232	}
233
234	return $data;
235	}
236
237	/**
238	* Blocks user url generation in sitemap.
239	* Consider the URL: http://example.com/wp-sitemap-users-1.xml will not return user URL XML.
240	*
241	* @return bool\|null If option sitemap enumeration enabled then return false else null/void will return.
242	*/
243	public function block_user_url_sitemap(): ?bool {
244	if (
245	in_array(
246	'enum-sitemap',
247	$this->get_enabled_user_enums(),
248	true
249	)
250	) {
251	return false;
252	}
253
254	return null;
255	}
256
257	/**
258	* Blocks the user provider sitemap before it is added from wp-sitemap.xml.
259	*
260	* @param WP_Sitemaps_Provider $provider Instance of a WP_Sitemaps_Provider.
261	* @param string $name Name of the sitemap provider.
262	*
263	* @return bool\|WP_Sitemaps_Provider If option sitemap enumeration enabled then return false else
264	* WP_Sitemaps_Provider instance.
265	*/
266	public function block_user_provider_sitemap( $provider, string $name ) {
267	if (
268	'users' === $name &&
269	in_array(
270	'enum-sitemap',
271	$this->get_enabled_user_enums(),
272	true
273	)
274	) {
275	return false;
276	}
277
278	return $provider;
279	}
280
281	/**
282	* Block user REST API endpoint for not logged-in access.
283	*
284	* @param WP_Error\|null\|true $errors WP_Error if authentication error, null if authentication
285	* method wasn't used, true if authentication succeeded.
286	*
287	* @return WP_Error\|null\|true $errors WP_Error if authentication error, null if authentication
288	* method wasn't used, true if authentication succeeded.
289	*/
290	public function block_rest_api_user_endpoint( $errors ) {
291	$request_uri = (string) filter_input( INPUT_SERVER, 'REQUEST_URI', FILTER_SANITIZE_URL ) ?? '';
292	$rest_route = (string) filter_input( INPUT_GET, 'rest_route', FILTER_SANITIZE_URL ) ?? '';
293
294	$is_url_match = preg_match( '/users/i', $request_uri ) !== 0 \|\|
295	preg_match( '/users/i', $rest_route ) !== 0;
296
297	if (
298	in_array(
299	'enum-rest',
300	$this->get_enabled_user_enums(),
301	true
302	) &&
303	$is_url_match &&
304	! is_user_logged_in()
305	) {
306	return new WP_Error(
307	'rest_cannot_access',
308	esc_html__( 'Only logged-in users can access the User endpoint REST API.', 'defender-security' ),
309	array( 'status' => rest_authorization_required_code() )
310	);
311	}
312
313	return $errors;
314	}
315
316	/**
317	* Block REST user endpoints for not logged-in access.
318	*
319	* @param array $endpoints The available endpoints.
320	*
321	* @return array
322	*/
323	public function block_rest_api_user_endpoints( $endpoints ) {
324	if ( is_user_logged_in() ) {
325	return $endpoints;
326	}
327	if ( ! in_array( 'enum-rest', $this->get_enabled_user_enums(), true ) ) {
328	return $endpoints;
329	}
330
331	$endpoints_to_remove = array(
332	'/wp/v2/users',
333	'/wp/v2/users/(?P<id>[\d]+)',
334	);
335
336	foreach ( $endpoints_to_remove as $route ) {
337	if ( isset( $endpoints[ $route ] ) ) {
338	unset( $endpoints[ $route ] );
339	}
340	}
341
342	return $endpoints;
343	}
344
345	/**
346	* Dynamically register rest_prepare_{$post_type} filters for all REST-exposed post types.
347	*
348	* @return void
349	*/
350	public function register_dynamic_post_type_filters() {
351	// Optimization: If REST API protection is disabled in the settings, we don't log anything at all.
352	if ( ! in_array( 'enum-rest', $this->get_enabled_user_enums(), true ) ) {
353	return;
354	}
355
356	$post_types = get_post_types( array( 'show_in_rest' => true ) );
357
358	foreach ( $post_types as $post_type ) {
359	add_filter( "rest_prepare_{$post_type}", array( $this, 'strip_author_link' ), 10, 1 );
360	}
361	}
362
363	/**
364	* Remove the 'author' relationship link from REST API responses for not logged-in access.
365	*
366	* @param WP_REST_Response $response The response object.
367	*
368	* @return WP_REST_Response
369	*/
370	public function strip_author_link( $response ) {
371	// This is a mandatory check because it is triggered at the moment of data transfer and knows for sure whether the user who sent the request is authorized.
372	if ( ! is_user_logged_in() ) {
373	$response->remove_link( 'author' );
374	}
375
376	return $response;
377	}
378	}
379