[wp-trac] [WordPress Trac] #61640: Issues in edit_link Function: Inconsistent Return Values, Insufficient Permission Error Handling, and Data Sanitization

[WordPress Trac]

#61640: Issues in edit_link Function: Inconsistent Return Values, Insufficient
Permission Error Handling, and Data Sanitization
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 Reporter:  shyamavadukar                  |      Owner:  (none)
     Type:  defect (bug)                   |     Status:  new
 Priority:  normal                         |  Milestone:  Awaiting Review
Component:  Security                       |    Version:  6.5.5
 Severity:  major                          |   Keywords:
  Focuses:  performance, coding-standards  |
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 Hello Sir/Ma'am,

 The edit_link function has several issues that need to be addressed to
 ensure proper functionality, security, and consistency:


 >>      1) Permission Error Handling: The function returns a WP_Error
 object for insufficient permissions, but this might not be user-friendly.
 It should use wp_die() to display a user-friendly error message.

         if (!current_user_can('manage_links')) {
                 wp_die(__('You need a higher level of permission.'));
         }

 >>      2) Inconsistent Return Values: The function returns mixed types
 (0, WP_Error, integer) inconsistently. All failure cases should return a
 WP_Error object for consistency.

         if (empty($link_url) || empty($link_name)) {
                 return new WP_Error('missing_data', __('Link URL and Name
 cannot be empty.'));
         }

 >>      3) Sanitization of Data: The function uses $_POST values without
 sufficient validation. All incoming data should be sanitized thoroughly.

         $link_url = isset($_POST['link_url']) ?
 esc_url_raw($_POST['link_url']) : '';

 >>      4)Data Integrity Check: No validation is performed to ensure the
 provided data is complete or correct before inserting/updating the link.
 Add validation checks to ensure data integrity.

         if (empty($link_url) || empty($link_name)) {
                 return new WP_Error('missing_data', __('Link URL and Name
 cannot be empty.'));
         }

 >>      5) Use of compact(): Using compact() for database operations might
 introduce vulnerabilities if variables are not sanitized correctly. Ensure
 all data passed to compact() is sanitized properly.

         $link_data = compact('link_url', 'link_name', 'link_image',
 'link_rss', 'link_visible');


 >> Steps to Reproduce
         1. Attempt to add or edit a link without the required permissions.
         2. Submit form data with empty or invalid values for URL and Name
 fields.

 >> Expected Behavior
         1. User-friendly error messages should be displayed for
 insufficient permissions.
         2. Consistent return types, with WP_Error objects for all error
 cases.
         3. All input data should be sanitized properly.
         4.Validation checks should ensure data integrity before database
 operations.

 >> Actual Behavior
         1. Insufficient permissions message is not user-friendly.
         2. Mixed return types causing inconsistency.
         3. Potential vulnerabilities due to improper data sanitization.
         4. Missing validation checks can lead to data integrity issues.

 >> Additional Context
   -- The issues were found while reviewing the edit_link function in the
 WordPress Bookmark Administration API.

 Best Regards
 -Shyama Vadukar

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/61640>
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