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PHP - Php Sql Injections
Hello,
I have been using the preg_match() to throw out invalid form characters and then both mysql_real_escape_string() and stripslashes() to escape data variables before using them with mysql. But how about messages from a text area for example on a contact form. You cant limit the characters for the user. Is escaping variables good enough to eliminate sql injections from user input? Similar TutorialsHi everyone, I have been the victim (at least i think) of SQL injection attacks!? I believe this as my contact us db table is full of 1's. How can i stop this from happening? Here's the contact form: Code: [Select] <form method="get" action="contact-send.php"> Name:<br /> <input type="text" name="name" id="name" size="30" /><br /> Email:<br /> <input type="email" name="email" id="email" size="30" /><br /> Your Question:<br /> <textarea name="question" id="question" rows="10" cols="50"></textarea><br /> <input type="submit" name="submit" value="send" /> </form> And here's the script 'contact-send.php': Code: [Select] <?PHP session_start(); include ('php only scripts/db.php'); if(isset($_POST['submit'])){ $name = $_POST['name']; $email = $_POST['email']; $question = $_POST['question']; //your code to insert variables into db can go here or after the if statement $query = "INSERT INTO contact_us (name, email, questions) VALUES ('" .$name. "', '" .$email. "', '" .$question. "')"; $result = mysql_query($query) or die(mysql_error()); echo $name."<br/>".$email."<br/>".$question; } header( 'Location: http://www.removalspace.com/contactconf.php' ); ?> Do i have to have if(isset on EACH variable? like on name, email and question too? I am trying to protect my guestbook entries from injections such as html, xss, and mysql injections. My php knowledge is very little. If possible, can I have some help please with protecting my entries. I have a few bits and pieces of code to protect my guestbook from injections that I got from some tutorials that I was reading. Code: [Select] <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <!-- Author: Reality Software Website: http://www.realitysoftware.ca Note: This is a free template released under the Creative Commons Attribution 3.0 license, which means you can use it in any way you want provided you keep the link to the author intact. --> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title></title> <link href="style.css" rel="stylesheet" type="text/css" /></head> <body> <!-- header --> <div id="header"> <div id="logo"><a href="index.html">Header</a></div> <div id="menu"> <ul> <li><a href="index.html">Home</a></li> <li><a href="">Link 1</a></li> <li><a href="">Link 2</a></li> <li><a href="">Link 3</a></li> <li><a href="">Contact</a></li> <li><a href="guestbook.php">Guestbook</a></li> </ul> </div> </div> <div id="icon"><a href="twitter.com/"> <img border="0" src="http://www.000webhost.com/forum/images/twitter.png" alt="twitter" width="58px;" height="53px;" /> </a></div> <!--end header --> <!-- main --> <div id="main"> <div id="content"> <div id="text"> <h1><strong>Guestbook</strong></h1> </div> <?php $input = is_numeric($input) ? intval($input) : mysql_real_escape_string($input);function sanitizeString($string) { return htmlentities( (string) $string, ENT_COMPAT, "UTF-8" ); } $preparedStatement = $db->prepare('SELECT * FROM guestbook WHERE name = :name'); $preparedStatement->execute(array(':name' => $name)); $rows = $preparedStatement->fetchAll(); $mysql_host = "localhost"; $mysql_database = "a7560006_guest"; $mysql_user = "a7560006_host"; $mysql_password = "mypassword"; // Connect to server and select database. mysql_connect("$mysql_host", "$mysql_user", "$mysql_password") or die("cannot connect server"); mysql_select_db("$mysql_database") or die("cannot select DB"); $tbl_name="guestbook"; // Table name $name = ($_POST['name']); $comment = ($_POST['comment']); $comment = stripslashes($comment); $name = stripslashes($name); $comment = str_replace("<","<",$comment); $name = str_replace("<","<",$name); $datetime=date("M-d-Y h:i:s A"); //date time $verif_box = ($_POST['verif_box']); if(md5($verif_box).'a4xn' != $_COOKIE['tntcon']){ ?> <table width="400" border="0" align="center"> <tr><td align="center"><h4>You have not entered captcha or entered incorrect captcha!</h4></td></tr> </table> </div> <!-- footer --> <div id="footer"> <div id="left_footer">© Copyright 2011<strong> Author </strong></div> <div id="right_footer"> <!-- Please do not change or delete this link. Read the license! Thanks. :-) --> Design by <a href="http://www.realitysoftware.ca" title="Website Design">Reality Software</a> </div> </div> <!-- end footer --> </div> <!-- end main --> </body> </html> <? exit; } if(empty($name) || empty($comment)) { ?> <table width="400" border="0" align="center"> <tr><td align="center"><h3>Sorry, all fields are required!</h3></td></tr> </table> <? } else { $sql="INSERT INTO $tbl_name (name, comment, datetime) VALUES ('$name', '$comment', '$datetime')"; $result=mysql_query($sql); //check if query successful if($result) { ?> <table width="400" border="0" align="center"> <tr><td align="center"><h3>Thank you for signing my guestbook!</h3></td></tr> </table> <? echo "<meta http-equiv='Refresh' content='1; URL=viewguestbook.php'>"; // link to view guestbook page } else { echo "ERROR"; } mysql_close(); } ?> </div> <!-- footer --> <div id="footer"> <div id="left_footer">© Copyright 2011<strong> Author </strong></div> <div id="right_footer"> <!-- Please do not change or delete this link. Read the license! Thanks. :-) --> Design by <a href="http://www.realitysoftware.ca" title="Website Design">Reality Software</a> </div> </div> <!-- end footer --> </div> <!-- end main --> </body> </html> I am having problems with a search feature I am using for a website I am building. Everything was working fine when I was testing on my local machine using EasyPHP 3.0. The issue I am having is that once I uploaded the site to a "live" server and tested it, my search function wouldn't work. The issue resides in the two lines with the magic quotes and the real escape string, for some reason those lines worked fine while testing using EasyPHP 3.0, but now I must delete those lines in order for my search function to work. The problem is that deleting those lines makes me vulnerable to an SQL injection. I have tried deleting just the magic quotes line and everything works properly, but then I am not seeing any kind of strip slashing/sanitizing when I enter in a statement like this into my search: a';DROP TABLE users; SELECT * FROM userinfo WHERE 't' = 't. Any help on this issue would be greatly appreciated! //get data $button = $_GET['submit']; if (get_magic_quotes_gpc() == 0){ $search = mysql_real_escape_string($_GET['search']); // clean up the search string } else { $search = $_GET['search']; $limit = 9; $page = $_GET['page']; if($page) $start = ($page - 1) * $limit; I also tried using the mysql_real_escape_string on my construct, but I get syntax errors because of the | being used before and after the $search_each. That | character must remain in place in order for my search to work the way I want it to. $x++; if ($x==1) $construct .= "keywords LIKE '%".mysql_real_escape_string(|$search_each|)."%'"; else $construct .= "AND keywords LIKE '%|$search_each|%'"; } Basically, I have the following code ($c2 is my connection variable): Code: [Select] $rid = $_GET['id']; $q = mysql_query("SELECT * FROM reports WHERE id = $rid", $c2) or die(mysql_error()); $report = mysql_fetch_array($q); $report is used later on to gather more information that is outputted to the user. However, if in the URL, someone were to put id=1', they would have an error message spit out to them (something along the lines of: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '\'' at line 1), indicating a SQL Injection exploit. How would I go about fixing this, and also preventing SQL Injection? Thanks a bunch, Mark htmlspecialchars($str, ENT_QUOTES, 'UTF-8');Using this code with UTF-8. I need someone to help craft up some smalll xss injections with this. I heard htmlspecialchars doesn't stop all xss attacks, so I'm wondering what's the most xss attack you can craft to load a simple cookie loader. (Basically, just simple javascript injection is all I'm trying to find, because people can use cookie loaders with it, and yeah, that's not good). Looking for your code to be posted, and once it is.. I'll copy it and submit it through the code I posted above and see if there is any vulnerabilities. (On my localhost server) Thanks! $str = user input. Oh, and here is the BBCODE regex that the code passes through before this function is returned on the text. $text = preg_replace( "#\[b\](.+?)\[/b\]#is", "<span class='b'>\\1</span>", $text );
$text = preg_replace( "#\[i\](.+?)\[/i\]#is", "<i>\\1</i>", $text );
$text = preg_replace( "#\[u\](.+?)\[/u\]#is", "<u>\\1</u>", $text );
$text = preg_replace( "#\[s\](.+?)\[/s\]#is", "<s>\\1</s>", $text );
//Spoiler
$text = preg_replace( "#\[right\](.+?)\[/right\]#is", "<div style='text-align:right'>$1</div>", $text );
//Beautiful Colors
$text = preg_replace( "%\[colou?r=([a-zA-Z]{3,20}|\#[0-9a-fA-F]{6}|\#[0-9a-fA-F]{3})](.+?)\[/colou?r\]%msi", '<span style="color: \\1">\\2</span>', $text );
$text = preg_replace( "%\[colou?r=(rgb\(\d{1,3}, ?\d{1,3}, ?\d{1,3}\))](.+?)\[/colou?r\]%msi", '<span style="color: \\1">\\2</span>', $text );
If anyone can craft up an XSS for this, I'd appreciate it. Because I need this to be secure.
Edited by Monkuar, 10 January 2015 - 06:33 PM. htmlspecialchars($str, ENT_QUOTES, 'UTF-8');Using this code with UTF-8. I need someone to help craft up some smalll xss injections with this. I heard htmlspecialchars doesn't stop all xss attacks, so I'm wondering what's the most xss attack you can craft to load a simple cookie loader. (Basically, just simple javascript injection is all I'm trying to find, because people can use cookie loaders with it, and yeah, that's not good). Looking for your code to be posted, and once it is.. I'll copy it and submit it through the code I posted above and see if there is any vulnerabilities. (On my localhost server) Thanks! $str = user input. Oh, and here is the BBCODE regex that the code passes through before this function is returned on the text. $text = preg_replace( "#\[b\](.+?)\[/b\]#is", "<span class='b'>\\1</span>", $text );
$text = preg_replace( "#\[i\](.+?)\[/i\]#is", "<i>\\1</i>", $text );
$text = preg_replace( "#\[u\](.+?)\[/u\]#is", "<u>\\1</u>", $text );
$text = preg_replace( "#\[s\](.+?)\[/s\]#is", "<s>\\1</s>", $text );
//Spoiler
$text = preg_replace( "#\[right\](.+?)\[/right\]#is", "<div style='text-align:right'>$1</div>", $text );
//Beautiful Colors
$text = preg_replace( "%\[colou?r=([a-zA-Z]{3,20}|\#[0-9a-fA-F]{6}|\#[0-9a-fA-F]{3})](.+?)\[/colou?r\]%msi", '<span style="color: \\1">\\2</span>', $text );
$text = preg_replace( "%\[colou?r=(rgb\(\d{1,3}, ?\d{1,3}, ?\d{1,3}\))](.+?)\[/colou?r\]%msi", '<span style="color: \\1">\\2</span>', $text );
If anyone can craft up an XSS for this, I'd appreciate it. Because I need this to be secure.
Edited by Monkuar, 10 January 2015 - 06:33 PM. Here is the code that i am using to accept data and display the data. To accept and add it in database i am using : $comment = $_POST['txtcomment']; $comment = @mysql_real_escape_string($comment); To display the data from DB i am using : $comment = $rowscomment['comment']; <?php echo nl2br($comment); ?> Please help me correct it....... I am still learning PHP. I'd like to use a text editor like this one: http://tinymce.moxiecode.com/examples/full.php for my forums. But I am not sure exactly how I would prevent abuse and injects to messed up the page, rather than being contained in the designated area it is meant for. Could some one please help me, I know htmlspecailchars will not work, since some of the code needs to render as html |
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