Issue status update for http://drupal.org/node/31197 Post a follow up: http://drupal.org/project/comments/add/31197 Project: Drupal Version: 4.6.0 Component: comment.module Category: bug reports Priority: critical Assigned to: Mogurito Reported by: Mogurito Updated by: Mogurito Status: patch (code needs review) *CORRECTION* (The comment is not complete) The source code interpreted by the browser, have html comment with the subject by each comment. For example, if we post a comment like 'Hello', Drupal write in the source code . But the problem come when a post is send with special characters like '<'. If we post a comment like '-->Hello XSS', the comment in the source code will be closed, provocating that "Hello XSS-->" string will be show in the page. If the "Hello XSS" string will be replaced by a script, we can get a XSS Attack. Solution Analize the subject string and replacing the special characters (<,>, ') for (&<, &>, &") How Adding this lines to the function comment_validate_form: $edit['subject'] = ereg_replace("<", "&<", $edit['subject']); $edit['subject'] = ereg_replace(">", "&>", $edit['subject']); $edit['subject'] = ereg_replace(""", "&"", $edit['subject']); Notes - Sorry, but my english is not very cool. Mogurito Previous comments: ------------------------------------------------------------------------ Wed, 14 Sep 2005 12:12:05 +0000 : Mogurito Attachment: http://drupal.org/files/issues/comment.module_13.diff (632 bytes) The source code interpreted by the browser, have html comment with the subject by each comment. For example, if we post a comment like 'Hello', Drupal write in the source code . But the problem come when a post is send with special characters like 'Hello XSS', the comment in the source code will be closed, provocating that "Hello XSS-->" string will be show in the page. If the "Hello XSS" string will be replaced by a script, we can get a XSS Attack. *Solution* Analize the subject string and replacing the special characters (, ') for (<, >, ") *How* Adding this lines to the function comment_validate_form: $edit['subject'] = ereg_replace("", ">", $edit['subject']); $edit['subject'] = ereg_replace("\'", """, $edit['subject']); *Notes* - Sorry, but my english is not very cool.