[wp-trac] [WordPress Trac] #23190: get_user_id_from_string() is returning wrong data

[WordPress Trac]

#23190: get_user_id_from_string() is returning wrong data
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 Reporter:  godhulii_1985    |       Type:  defect (bug)
   Status:  new              |   Priority:  normal
Milestone:  Awaiting Review  |  Component:  General
  Version:  3.5              |   Severity:  major
 Keywords:  needs-docs       |
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 '''Background'''[[BR]]
 I was developing my custom theme and used google-oauth for auto user
 login. Here, I used user's google id (not login user-id, the profile id
 which is totally numeric) so that I can identify the user later. To create
 new user I used wp_insert_user().

 The newly created user can update his/her initial default password and it
 will fail in the wp login process so everytime I call user_signon()
 function I call wp_update_user() to update his/her password to default
 [additionally, I disable password field in wp-admin area and that works
 for general user but as you know it is not hacker proof]

 '''Here begins the problem'''[[BR]]
 Lets assume google says that the oauth user's id is: 123456. So, I created
 an user with user-id: 123456. Wordpress assigned 99 to the user (that is
 www.example.com/?author=99 will redirect to this user's profile)

 Now, when I call get_user_id_from_string('123456'), I expect 99 but I get
 123456. I think it is a security risk because user-id is the users's
 database primary key type id (which is 99 in this case).

 I looked into the core "wp-includes => ms-functions.php =>
 get_user_id_from_string()" and found this segment:

         elseif ( is_numeric( $string ) ) {
                 $user_id = $string;
         } else {
                 $user = get_user_by('login', $string);
                 if ( $user )
                         $user_id = $user->ID;
         }

 Here, is_numeric() gets precendance and I do not get my desired id (99) as
 my input string (or user-login-name) was 123456 which passes is_numeric()
 function.

 '''Problem defination'''[[BR]]
 The developers considered wp user-login-id to be alphaneumeric (I think)
 but in the documentation it is mentioned that: "user_login     A string
 that contains the user's username for logging in. " in
 http://codex.wordpress.org/Function_Reference/wp_insert_user page. It is
 not mentioned it should be alphaneumeric or not.


 Right now I have solved the issue by prepending 'g' infront of the oauth
 codes so I'm using 'g123456' as user-login-id in wp_insert_user() but I
 think this issue should be considered as security risk because if there is
 no binding on wp_insert_user() with a numeric value (123456) as user-id
 then get_user_id_from_string() should also respect this choice and return
 99 here instead of 123456, otherwise wrong user will be signed into in
 this scenario.

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Ticket URL: <http://core.trac.wordpress.org/ticket/23190>
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