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

class-prevent-enum-users.php in Defender Security – Malware Scanner, Login Security & Firewall 5.9.0, 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_Sitemaps_Provider;
13	use WP_Defender\Traits\Security_Tweaks_Option;
14
15	/**
16	* Prevent user enumeration.
17	*/
18	class Prevent_Enum_Users extends Abstract_Security_Tweaks implements Security_Key_Const_Interface {
19
20	use Security_Tweaks_Option;
21
22	/**
23	* The slug identifier for this tweak.
24	*
25	* @var string
26	*/
27	public string $slug = 'prevent-enum-users';
28
29	/**
30	* Status to check if the issue has been resolved.
31	*
32	* @var bool
33	*/
34	public $resolved = false;
35
36	/**
37	* Enabled user enumerations list.
38	*
39	* @var array
40	*/
41	private $enabled_user_enums = array();
42
43	/**
44	* Check whether the issue has been resolved or not.
45	*
46	* @return bool
47	*/
48	public function check(): bool {
49	return $this->resolved;
50	}
51
52	/**
53	* Here is the code for processing.
54	*
55	* @return bool
56	*/
57	public function process(): bool {
58	return true;
59	}
60
61	/**
62	* This is for un-do stuff that has been done in @process.
63	*
64	* @return bool
65	*/
66	public function revert(): bool {
67	return true;
68	}
69
70	/**
71	* Shield up.
72	*
73	* @return void
74	*/
75	public function shield_up() {
76	$this->resolved = true;
77
78	if ( is_admin() \|\| defender_is_wp_cli() ) {
79	return;
80	}
81
82	add_filter( 'oembed_response_data', array( $this, 'oembed_author_filter' ), 99 );
83	add_filter( 'wp_sitemaps_users_pre_url_list', array( $this, 'block_user_url_sitemap' ), 99, 0 );
84	add_filter( 'wp_sitemaps_add_provider', array( $this, 'block_user_provider_sitemap' ), 99, 2 );
85	add_filter( 'rest_authentication_errors', array( $this, 'block_rest_api_user_endpoint' ) );
86
87	$query = defender_get_data_from_request( 'QUERY_STRING', 's' );
88	if ( ! is_string( $query ) \|\| '' === $query ) {
89	return;
90	}
91
92	$this->maybe_block( $query );
93
94	add_filter( 'redirect_canonical', array( $this, 'maybe_block' ) );
95	}
96
97	/**
98	* Maybe block the request if it's trying to access the author page with query param.
99	*
100	* @param string $request Request of current page.
101	*
102	* @return string
103	*/
104	public function maybe_block( string $request ) {
105	if ( ! current_user_can( 'edit_others_posts' ) ) {
106	$params = array();
107	wp_parse_str( strtolower( $request ), $params );
108
109	if (
110	isset( $params['author'] )
111	&& is_scalar( $params['author'] )
112	&& '' !== preg_replace( '/[^0-9,-]/', '', $params['author'] )
113	) {
114	wp_die(
115	esc_html__( 'Sorry, you are not allowed to access this page', 'defender-security' ),
116	esc_html__( 'Forbidden', 'defender-security' ),
117	403
118	);
119	}
120	}
121
122	return $request;
123	}
124
125	/**
126	* Retrieve the tweak's label.
127	*
128	* @return string
129	*/
130	public function get_label(): string {
131	return esc_html__( 'Prevent user enumeration', 'defender-security' );
132	}
133
134	/**
135	* Get the error reason.
136	*
137	* @return string
138	*/
139	public function get_error_reason(): string {
140	return esc_html__( 'User enumeration is currently allowed.', 'defender-security' );
141	}
142
143	/**
144	* Return a summary data of this tweak.
145	*
146	* @return array
147	*/
148	public function to_array(): array {
149	return array(
150	'slug' => $this->slug,
151	'title' => $this->get_label(),
152	'errorReason' => $this->get_error_reason(),
153	'successReason' => esc_html__( 'User enumeration is currently blocked, nice work!', 'defender-security' ),
154	'misc' => array(),
155	'bulk_description' => esc_html__(
156	'To brute force your login, hackers and bots can simply type the query string ?author=1, ?author=2 and so on, which will redirect the page to /author/username/ - bam, the bot now has your usernames to begin brute force attacks with. We can add a .htaccess file to your site to prevent the redirection.',
157	'defender-security'
158	),
159	'bulk_title' => $this->get_label(),
160	);
161	}
162
163	/**
164	* Getter method of enabled_user_enums.
165	*
166	* @return array Return array of enabled enumeration options.
167	*/
168	public function get_enabled_user_enums(): array {
169	$enabled_user_enums = $this->get_option( 'enabled_user_enums' );
170
171	$this->enabled_user_enums = is_null( $enabled_user_enums )
172	? array()
173	: (array) $enabled_user_enums;
174
175	return $this->enabled_user_enums;
176	}
177
178	/**
179	* Setter method of enabled_user_enums.
180	*
181	* @param array $value Array of enabled user enumeration options.
182	*
183	* @return bool Return true if value updated, otherwise false.
184	*/
185	public function set_enabled_user_enums( $value ): bool {
186	$this->enabled_user_enums = ! is_array( $value ) ? (array) $value : $value;
187
188	return $this->update_option(
189	'enabled_user_enums',
190	$this->enabled_user_enums
191	);
192	}
193
194	/**
195	* Filters the author detail from oEmbed response data.
196	*
197	* @param array $data The response data.
198	*
199	* @return array $data The response data.
200	*/
201	public function oembed_author_filter( $data ) {
202	if (
203	is_array( $data ) &&
204	in_array(
205	'enum-oembed',
206	$this->get_enabled_user_enums(),
207	true
208	)
209	) {
210	unset( $data['author_name'], $data['author_url'] );
211	}
212
213	return $data;
214	}
215
216	/**
217	* Blocks user url generation in sitemap.
218	* Consider the URL: http://example.com/wp-sitemap-users-1.xml will not return user URL XML.
219	*
220	* @return bool\|null If option sitemap enumeration enabled then return false else null/void will return.
221	*/
222	public function block_user_url_sitemap(): ?bool {
223	if (
224	in_array(
225	'enum-sitemap',
226	$this->get_enabled_user_enums(),
227	true
228	)
229	) {
230	return false;
231	}
232
233	return null;
234	}
235
236	/**
237	* Blocks the user provider sitemap before it is added from wp-sitemap.xml.
238	*
239	* @param WP_Sitemaps_Provider $provider Instance of a WP_Sitemaps_Provider.
240	* @param string $name Name of the sitemap provider.
241	*
242	* @return bool\|WP_Sitemaps_Provider If option sitemap enumeration enabled then return false else
243	* WP_Sitemaps_Provider instance.
244	*/
245	public function block_user_provider_sitemap( $provider, string $name ) {
246	if (
247	'users' === $name &&
248	in_array(
249	'enum-sitemap',
250	$this->get_enabled_user_enums(),
251	true
252	)
253	) {
254	return false;
255	}
256
257	return $provider;
258	}
259
260	/**
261	* Block user REST API endpoint for not logged-in access.
262	*
263	* @param WP_Error\|null\|true $errors WP_Error if authentication error, null if authentication
264	* method wasn't used, true if authentication succeeded.
265	*
266	* @return WP_Error\|null\|true $errors WP_Error if authentication error, null if authentication
267	* method wasn't used, true if authentication succeeded.
268	*/
269	public function block_rest_api_user_endpoint( $errors ) {
270	$request_uri = (string) filter_input( INPUT_SERVER, 'REQUEST_URI', FILTER_SANITIZE_URL ) ?? '';
271	$rest_route = (string) filter_input( INPUT_GET, 'rest_route', FILTER_SANITIZE_URL ) ?? '';
272
273	$is_url_match = preg_match( '/users/i', $request_uri ) !== 0 \|\|
274	preg_match( '/users/i', $rest_route ) !== 0;
275
276	if (
277	in_array(
278	'enum-rest',
279	$this->get_enabled_user_enums(),
280	true
281	) &&
282	$is_url_match &&
283	! is_user_logged_in()
284	) {
285	return new WP_Error(
286	'rest_cannot_access',
287	esc_html__( 'Only logged-in users can access the User endpoint REST API.', 'defender-security' ),
288	array( 'status' => rest_authorization_required_code() )
289	);
290	}
291
292	return $errors;
293	}
294	}
295