|  support |  documentation |  report a bug |  advanced search |  search howto |  statistics |  random bug |  login
Bug #50389 filter_var with FILTER_SANITIZE_STRING misses ` character
Submitted: 2009-12-04 17:43 UTC Modified: 2009-12-07 13:44 UTC
Avg. Score:4.0 ± 0.0
Reproduced:1 of 1 (100.0%)
Same Version:1 (100.0%)
Same OS:1 (100.0%)
From: aldekein at myevil dot info Assigned:
Status: Closed Package: Filter related
PHP Version: 5.2.11 OS: Windows 7
Private report: No CVE-ID: None
View Add Comment Developer Edit
Welcome! If you don't have a Git account, you can't do anything here.
You can add a comment by following this link or if you reported this bug, you can edit this bug over here.
Block user comment
Status: Assign to:
Bug Type:
From: aldekein at myevil dot info
New email:
PHP Version: OS:


 [2009-12-04 17:43 UTC] aldekein at myevil dot info
I try to sanitize:
Bug: "'`

I get:
Bug: \"\'`

The ` character is not sanitized. Why?

Reproduce code:


echo filter_var("\"'`", FILTER_SANITIZE_STRING);

Expected result:

00 = code for ` character.

Actual result:


Add a Patch

Pull Requests

Add a Pull Request


AllCommentsChangesGit/SVN commitsRelated reports
 [2009-12-07 08:06 UTC]
Oh, it was backquote, didn't paste well. :) Anyway, why should that be stripped..? Or why it should end up as null..? 
 [2009-12-07 09:36 UTC] aldekein at myevil dot info
This filter removes data that is potentially harmful for the application. I expected to get a clear string that could be used in MySQL, for example. But the backquote is dangerous in MySQL statements.
 [2009-12-07 13:44 UTC]
The FILTER_FLAG_STRIP_HIGH flag only strips chars with value > 127, ` 
(backtick) is 96, so it does not get stripped.

I've added FILTER_FLAG_STRIP_BACKTICK filter for PHP 5.3+ that will 
allow removal of the backtick character.
PHP Copyright © 2001-2024 The PHP Group
All rights reserved.
Last updated: Fri May 24 14:01:30 2024 UTC